Add issue templates for feature requests and bug reports (#153)

* Add issue template for feature requests and bug reports

* Update .github/ISSUE_TEMPLATE/config.yml
Co-authored-by: Anton Lozhkov <anton@huggingface.co>

.github/ISSUE_TEMPLATE/bug-report.yml

+name: "\U0001F41B Bug Report"
+description: Report a bug on diffusers
+labels: [ "bug" ]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to fill out this bug report!
+  - type: textarea
+    id: bug-description
+    attributes:
+      label: Describe the bug
+      description: A clear and concise description of what the bug is. If you intend to submit a pull request for this issue, tell us in the description. Thanks!
+      placeholder: Bug description
+    validations:
+      required: true
+  - type: textarea
+    id: reproduction
+    attributes:
+      label: Reproduction
+      description: Please provide a minimal reproducible code which we can copy/paste and reproduce the issue.
+      placeholder: Reproduction
+  - type: textarea
+    id: logs
+    attributes:
+      label: Logs
+      description: "Please include the Python logs if you can."
+      render: shell
+  - type: textarea
+    id: system-info
+    attributes:
+      label: System Info
+      description: Please share your system info with us,
+      render: shell
+      placeholder: diffusers version, Python Version, etc
+    validations:
+      required: true

.github/ISSUE_TEMPLATE/config.yml

+contact_links:
+  - name: Forum
+    url: https://discuss.huggingface.co/c/discussion-related-to-httpsgithubcomhuggingfacediffusers/63
+    about: General usage questions and community discussions
+  - name: Blank issue
+    url: https://github.com/huggingface/diffusers/issues/new
+    about: Please note that the Forum is in most places the right place for discussions

.github/ISSUE_TEMPLATE/feature_request.md

+---
+name: "\U0001F680 Feature request"
+about: Suggest an idea for this project
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.