compose-jb/.github/PULL_REQUEST_TEMPLATE.md

Describe proposed changes and the issue being fixed

<!-- Optional -->
Fixes [link to the issue]

## Testing
<!-- Optional -->
Describe how you tested your changes. If possible and needed:
- Test it on a sample project
- Write unit tests
- Provide a code snippet

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This should be tested by QA

## Release Notes
<!--
If we definitely shouldn't add Release Notes, add only N/A.

Or enumerate sections, subsections and all changes.

Possible sections:
- Highlights
- Known Issues
- Breaking Changes
- Features
- Fixes

Possible subsections:
- Multiple Platforms
- iOS
- Desktop
- Web
- Android
- Resources
- Gradle Plugin
-->
### Section - Subsection
- Describe a change for adding it to https://github.com/JetBrains/compose-multiplatform/blob/master/CHANGELOG.md
- _(prerelease fix)_ Fix some bug that introduced in a prerelease version (dev/beta). It will be included in a dev/beta changelog, but excluded from a stable changelog

### Section - Subsection
- Describe another change if needed