Update web hot reload template.

Make the file a yaml file and change:
1) Refer to the new "Known issues" project.
2) Update the version to command to be "flutter --version" instead of "dart --version".
3) Include code sample and repro instruction inputs.

Change-Id: Ia655d860cc5547097a292101a92439109916bee0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/409204
Reviewed-by: Kevin Moore <[email protected]>
Commit-Queue: Nate Biggs <[email protected]>

Author: natebiggs

.github/ISSUE_TEMPLATE/6_web_hot_reload.md

@@ -0,0 +1,41 @@
+name: Report an issue related to Dart Web Stateful Hot Reload
+description: |
+  Create an issue specific to the Stateful Hot Reload feature available via the Dart web development compiler (DDC).
+labels: ["area-web", "web-hot-reload", "web-dev-compiler"]
+assignees:
+ - nshahan
+ - biggs0125
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Begin by checking our [Web Hot Reload - Known Issues](https://github.com/orgs/dart-lang/projects/107/views/1) project to ensure this is not a known issue.
+
+        If a similar issue has not been filed yet, use this template to file a new issue with the correct labels.
+
+        If the issue you are experiencing presents itself in Flutter, please file an issue here in the Dart repository. We will forward any Flutter-specific issues to the Flutter repository as needed.
+
+        Note: Hot reload rejections are expected errors that occur when a change is made that prevents the compiler from generating valid hot reload code. If you encounter such a rejection you must either undo the change to reload or perform a full hot restart.
+
+  - type: textarea
+    attributes:
+      label: Steps to reproduce
+      description: Please tell us how to reproduce the problem you are running into.
+      placeholder: |
+        1. ...
+        2. ...
+        3. ...
+  - type: textarea
+    attributes:
+      label: Code sample
+      description: |
+        If possible please include the code involved in the error or a similar minimal reproduction of the issue. Please also include any previous versions of the code prior to hot reloading that may have contributed to the issue.
+  - type: textarea
+    attributes:
+      label: Flutter version
+      description: Please include the version of Flutter this issue was discovered in. If you are using a published SDK (e.g. from the main channel) please include the verison emitted by `flutter --version`. If you're using a locally built SDK, please include the git commit of your local Flutter checkout.
+  - type: markdown
+    attributes:
+      value: |
+        Thank you for helping improve hot reload on the web!
+