Convert issue templates to issue forms.

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,80 @@
+name: Bug Report (Traefik)
+description: Create a report to help us improve.
+body:
+  - type: checkboxes
+    id: terms
+    attributes:
+      label: Welcome!
+      description: |
+        The issue tracker is for reporting bugs and feature requests only. For end-user related support questions, please refer to one of the following:
+        - the Traefik community forum: https://community.containo.us/
+
+        The configurations between 1.X and 2.X are NOT compatible. Please have a look [here](https://doc.traefik.io/traefik/getting-started/configuration-overview/).
+
+        DO NOT FILE ISSUES FOR GENERAL SUPPORT QUESTIONS.
+      options:
+        - label: Yes, I've searched similar issues on [GitHub](https://github.com/traefik/traefik/issues) and didn't find any.
+          required: true
+        - label: Yes, I've searched similar issues on the [Traefik community forum](https://community.containo.us) and didn't find any.
+          required: true
+
+  - type: textarea
+    attributes:
+      label: What did you do?
+      description: |
+        How to write a good bug report?
+
+        - Respect the issue template as much as possible.
+        - The title should be short and descriptive.
+        - Explain the conditions which led you to report this issue: the context.
+        - The context should lead to something, an idea or a problem that you’re facing.
+        - Remain clear and concise.
+        - Format your messages to help the reader focus on what matters and understand the structure of your message, use [Markdown syntax](https://help.github.com/articles/github-flavored-markdown)
+      placeholder: What did you do?
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: What did you see instead?
+      placeholder: What did you see instead?
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: What version of Traefik are you using?
+      description: |
+        `latest` is not considered as a valid version.
+
+        Output of `traefik version`.
+
+        For the Traefik Docker image (`docker run [IMAGE] version`), example:
+        ```console
+        $ docker run traefik version
+        ```
+      placeholder: Paste your output here.
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: What is your environment & configuration?
+      description: arguments, toml, provider, platform, ...
+      placeholder: Add information here.
+      value: |
+        ```yaml
+        # (paste your configuration here)
+        ```
+
+        Add more configuration information here.
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: If applicable, please paste the log output in DEBUG level
+      description: "`--log.level=DEBUG` switch."
+      placeholder: Paste your output here.
+    validations:
+      required: false