Update issue templates

.github/ISSUE_TEMPLATE/bug_report.md

----
-name: Bug report
-about: Create a report to help us improve torchvision
-title: ''
-labels: ''
-assignees: ''
-
----
-
-## 🐛 Bug
-
-<!-- A clear and concise description of what the bug is. -->
-
-## To Reproduce
-
-Steps to reproduce the behavior:
-
-1.
-1.
-1.
-
-<!-- If you have a code sample, error messages, stack traces, please provide it here as well -->
-
-## Expected behavior
-
-<!-- A clear and concise description of what you expected to happen. -->
-
-## Environment
-
-Please copy and paste the output from our
-[environment collection script](https://raw.githubusercontent.com/pytorch/pytorch/master/torch/utils/collect_env.py)
-(or fill out the checklist below manually).
-
-You can get the script and run it with:
-```
-wget https://raw.githubusercontent.com/pytorch/pytorch/master/torch/utils/collect_env.py
-# For security purposes, please check the contents of collect_env.py before running it.
-python collect_env.py
-```
-
- - PyTorch / torchvision Version (e.g., 1.0 / 0.4.0):
- - OS (e.g., Linux):
- - How you installed PyTorch / torchvision (`conda`, `pip`, source):
- - Build command you used (if compiling from source):
- - Python version:
- - CUDA/cuDNN version:
- - GPU models and configuration:
- - Any other relevant information:
-
-## Additional context
-
-<!-- Add any other context about the problem here. -->

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

----
-name: "Issue: \U0001F4DA Documentation"
-about: Report an issue related to https://pytorch.org/docs
-title: ''
-labels: ''
-assignees: ''
-
----
-
-## 📚 Documentation
-
-<!-- A clear and concise description of what content in https://pytorch.org/docs is an issue. If this has to do with the general https://pytorch.org website, please file an issue at https://github.com/pytorch/pytorch.github.io/issues/new/choose instead. If this has to do with https://pytorch.org/tutorials, please file an issue at https://github.com/pytorch/tutorials/issues/new -->

.github/ISSUE_TEMPLATE/issue---questions-help-support.md

----
-name: 'Issue: ❓Questions/Help/Support'
-about: Do you need support? We have resources.
-title: ''
-labels: ''
-assignees: ''
-
----
-
-## ❓ Questions and Help
-
-### Please note that this issue tracker is not a help form and this issue will be closed.
-
-We have a set of [listed resources available on the website](https://pytorch.org/resources). Our primary means of support is our discussion forum:
-
-- [Discussion Forum](https://discuss.pytorch.org/)