Revise issue templates (#8492)

Revise issue templates for readability improvement
Add prerequisites

.github/ISSUE_TEMPLATE/00-official-bug-report-issue.md

 ---
-name: Bug Report for Official Models
-about: Use this template for reporting a bug for projects under the “official” folder
+name: "[Official Model] Bug Report"
+about: Use this template for reporting a bug for the “official” directory
 labels: type:bug,models:official
 
 ---
-<!--
-Please make sure that this is a bug. 
 
-As per our GitHub Policy (https://github.com/tensorflow/models/blob/master/ISSUES.md), we only address code bugs, documentation issues, and feature requests on GitHub.
+# Prerequisites
 
-Please go to Stack Overflow (http://stackoverflow.com/questions/tagged/tensorflow-model-garden) for help and support.
--->
+Please answer the following questions for yourself before submitting an issue.
+
+- [ ] I am using the latest TensorFlow Model Garden release and TensorFlow 2.
+- [ ] I am reporting the issue to the correct repository. (Model Garden official or research directory)
+- [ ] I checked to make sure that this issue has not been filed already.
+
+## 1. The entire URL of the file you are using
+
+https://github.com/tensorflow/models/tree/master/official/...
+
+## 2. Describe the bug
+
+A clear and concise description of what the bug is.
+
+## 3. Steps to reproduce
+
+Steps to reproduce the behavior.
+
+## 4. Expected behavior
+
+A clear and concise description of what you expected to happen.
+
+## 5. Additional context
+
+Include any logs that would be helpful to diagnose the problem.
+
+## 6. System information
 
-**System information**
-- Have I written custom code (as opposed to using a stock example script provided in TensorFlow):
 - OS Platform and Distribution (e.g., Linux Ubuntu 16.04):
-- Mobile device (e.g., Pixel 4, Samsung Galaxy 10) if the issue happens on mobile device:
+- Mobile device name if the issue happens on a mobile device:
 - TensorFlow installed from (source or binary):
 - TensorFlow version (use command below):
 - Python version:
@@ -25,25 +46,14 @@ Please go to Stack Overflow (http://stackoverflow.com/questions/tagged/tensorflo
 - GPU model and memory:
 
 <!-- 
-You can collect some of this information using our environment capture (https://github.com/tensorflow/tensorflow/tree/master/tools/tf_env_collect.sh)
-You can also obtain the TensorFlow version with: 
+Collect system information using our environment capture script.
+https://github.com/tensorflow/tensorflow/tree/master/tools/tf_env_collect.sh
+
+You can also obtain the TensorFlow version with:
 
 1. TensorFlow 1.0
-`python -c "import tensorflow as tf; print(tf.GIT_VERSION, tf.VERSION)"` 
+`python -c "import tensorflow as tf; print(tf.GIT_VERSION, tf.VERSION)"`
 
 2. TensorFlow 2.0
 `python -c "import tensorflow as tf; print(tf.version.GIT_VERSION, tf.version.VERSION)"`
 -->
-
-**Please provide the entire URL of the model you are using?**
-<!-- (e.g., https://github.com/tensorflow/models/tree/master/official/nlp/bert) -->
-
-**Describe the current behavior**
-
-**Describe the expected behavior**
-
-**Code to reproduce the issue**
-<!-- Provide a reproducible test case that is the bare minimum necessary to generate the problem. -->
-
-**Other info / logs**
-<!-- Include any logs or source code that would be helpful to diagnose the problem. If including tracebacks, please include the full traceback. Large logs and files should be attached. -->

.github/ISSUE_TEMPLATE/10-official-documentation-issue.md

 ---
-name: Documentation Issue for Official Models
+name: "[Official Model] Documentation Issue"
 about: Use this template for reporting a documentation issue for projects under the “official” folder
 labels: type:docs,models:official
 
 ---
 
-**Documentation URL(s) with the issue:**
-e.g., https://github.com/tensorflow/models/tree/master/official/README.md
+# Prerequisites
 
-**Description of the issue (what needs to be changed):**
+Please answer the following question for yourself before submitting an issue.
+
+- [ ] I checked to make sure that this issue has not been filed already.
+
+## 1. The entire URL of the documentation with the issue
+
+https://github.com/tensorflow/models/tree/master/official/...
+
+## 2. Describe the issue
+
+A clear and concise description of what needs to be changed.

.github/ISSUE_TEMPLATE/20-official-feature-request-issue.md

 ---
-name: Feature request for Official Models
-about: Use this template for raising a feature request for projects under the “official” folder
+name: "[Official Model] Feature request"
+about: Use this template for raising a feature request for the “official” directory
 labels: type:feature,models:official
 
 ---
 
-**Please provide the entire URL of the model you are using?**
-e.g., https://github.com/tensorflow/models/tree/master/official/...
+# Prerequisites
+
+Please answer the following question for yourself before submitting an issue.
+
+- [ ] I checked to make sure that this feature has not been requested already.
+
+## 1. The entire URL of the file you are using
+
+https://github.com/tensorflow/models/tree/master/official/...
+
+## 2. Describe the feature you request
 
-**Describe the feature you request**
 A clear and concise description of what you want to happen.
 
-**Additional context**
+## 3. Additional context
+
 Add any other context about the feature request here.
 
-**Are you willing to contribute it (Yes/No)?**
+## 4. Are you willing to contribute it? (Yes or No)

.github/ISSUE_TEMPLATE/30-research-bug-report-issue.md

 ---
-name: Bug Report for Research Models
-about: Use this template for reporting a bug for projects under the “research” folder
+name: "[Research Model] Bug Report"
+about: Use this template for reporting a bug for the “research” directory
 labels: type:bug,models:research
 
 ---
-<!--
-Please make sure that this is a bug. 
+# Prerequisites
 
-As per our GitHub Policy (https://github.com/tensorflow/models/blob/master/ISSUES.md), we only address code bugs, documentation issues, and feature requests on GitHub.
+Please answer the following questions for yourself before submitting an issue.
 
-Please go to Stack Overflow (http://stackoverflow.com/questions/tagged/tensorflow-model-garden) for help and support.
+- [ ] I am using the latest TensorFlow Model Garden release and TensorFlow 2.
+- [ ] I am reporting the issue to the correct repository. (Model Garden official or research directory)
+- [ ] I checked to make sure that this issue has not already been filed.
 
-The research models (https://github.com/tensorflow/models/tree/master/research) are a large collection of models implemented in TensorFlow by researchers. They are not officially supported. It is up to the individual researchers to maintain the models and/or provide support on issues and pull requests.
--->
+## 1. The entire URL of the file you are using
+
+https://github.com/tensorflow/models/tree/master/research/...
+
+## 2. Describe the bug
+
+A clear and concise description of what the bug is.
+
+## 3. Steps to reproduce
+
+Steps to reproduce the behavior.
+
+## 4. Expected behavior
+
+A clear and concise description of what you expected to happen.
+
+## 5. Additional context
+
+Include any logs that would be helpful to diagnose the problem.
+
+## 6. System information
 
-**System information**
-- Have I written custom code (as opposed to using a stock example script provided in TensorFlow):
 - OS Platform and Distribution (e.g., Linux Ubuntu 16.04):
-- Mobile device (e.g., Pixel 4, Samsung Galaxy 10) if the issue happens on mobile device:
+- Mobile device name if the issue happens on a mobile device:
 - TensorFlow installed from (source or binary):
 - TensorFlow version (use command below):
 - Python version:
@@ -27,25 +45,14 @@ The research models (https://github.com/tensorflow/models/tree/master/research)
 - GPU model and memory:
 
 <!-- 
-You can collect some of this information using our environment capture (https://github.com/tensorflow/tensorflow/tree/master/tools/tf_env_collect.sh)
-You can also obtain the TensorFlow version with: 
+Collect system information using our environment capture script.
+https://github.com/tensorflow/tensorflow/tree/master/tools/tf_env_collect.sh
+
+You can also obtain the TensorFlow version with:
 
 1. TensorFlow 1.0
-`python -c "import tensorflow as tf; print(tf.GIT_VERSION, tf.VERSION)"` 
+`python -c "import tensorflow as tf; print(tf.GIT_VERSION, tf.VERSION)"`
 
 2. TensorFlow 2.0
 `python -c "import tensorflow as tf; print(tf.version.GIT_VERSION, tf.version.VERSION)"`
 -->
-
-**Please provide the entire URL of the model you are using?**
-<!-- (e.g., https://github.com/tensorflow/models/tree/master/official/nlp/bert) -->
-
-**Describe the current behavior**
-
-**Describe the expected behavior**
-
-**Code to reproduce the issue**
-<!-- Provide a reproducible test case that is the bare minimum necessary to generate the problem. -->
-
-**Other info / logs**
-<!-- Include any logs or source code that would be helpful to diagnose the problem. If including tracebacks, please include the full traceback. Large logs and files should be attached. -->

.github/ISSUE_TEMPLATE/40-research-documentation-issue.md

 ---
-name: Documentation Issue for Research Models
-about: Use this template for reporting a documentation issue for projects under the “research” folder
+name: "[Research Model] Documentation Issue"
+about: Use this template for reporting a documentation issue for the “research” directory
 labels: type:docs,models:research
 
 ---
-<!--
-Please make sure that this is a documentation issue. 
 
-As per our GitHub Policy (https://github.com/tensorflow/models/blob/master/ISSUES.md), we only address code bugs, documentation issues, and feature requests on GitHub.
+# Prerequisites
 
-Please go to Stack Overflow (http://stackoverflow.com/questions/tagged/tensorflow-model-garden) for help and support.
+Please answer the following question for yourself before submitting an issue.
 
-The research models (https://github.com/tensorflow/models/tree/master/research) are a large collection of models implemented in TensorFlow by researchers. They are not officially supported. It is up to the individual researchers to maintain the models and/or provide support on issues and pull requests.
--->
+- [ ] I checked to make sure that this issue has not been filed already.
 
-**Documentation URL(s) with the issue:**
-<!-- Please provide a link to the documentation entry, for example: https://github.com/tensorflow/models/blob/master/research/README.md -->
+## 1. The entire URL of the documentation with the issue
 
-**Description of the issue (what needs to be changed):**
+https://github.com/tensorflow/models/tree/master/research/...
+
+## 2. Describe the issue
+
+A clear and concise description of what needs to be changed.

.github/ISSUE_TEMPLATE/50-research-feature-request-issue.md

 ---
-name: Feature Request for Research Models
-about: Use this template for raising a feature request for projects under the “research” folder
+name: "[Research Model] Feature Request"
+about: Use this template for raising a feature request for the “research” directory
 labels: type:feature,models:research
 
 ---
-<!--
-Please make sure that this is a feature request. 
 
-As per our GitHub Policy (https://github.com/tensorflow/models/blob/master/ISSUES.md), we only address code bugs, documentation issues, and feature requests on GitHub.
+# Prerequisites
 
-Please go to Stack Overflow (http://stackoverflow.com/questions/tagged/tensorflow-model-garden) for help and support.
+Please answer the following question for yourself before submitting an issue.
 
-The research models (https://github.com/tensorflow/models/tree/master/research) are a large collection of models implemented in TensorFlow by researchers. They are not officially supported. It is up to the individual researchers to maintain the models and/or provide support on issues and pull requests.
--->
+- [ ] I checked to make sure that this feature has not been requested already.
 
-**Please provide the entire URL of the model you are using?**
-<!-- (e.g., https://github.com/tensorflow/models/tree/master/official/nlp/bert) -->
+## 1. The entire URL of the file you are using
 
-**Describe the feature you request and the current behavior/state.**
+https://github.com/tensorflow/models/tree/master/research/...
 
-**Are you willing to contribute it (Yes/No)?**
+## 2. Describe the feature you request
 
-**Any other info.**
+A clear and concise description of what you want to happen.
+
+## 3. Additional context
+
+Add any other context about the feature request here.
+
+## 4. Are you willing to contribute it? (Yes or No)