Housekeeping/improve issue templates (#13074)

* Update bug_report.md

* Update feature_request.md

.github/ISSUE_TEMPLATE/bug_report.md

@@ -6,10 +6,10 @@ labels: bug
 assignees: ''
 ---
 
-**Describe the bug**
+## Describe the bug
 A clear and concise description of what the bug is.
 
-**To Reproduce**
+## To Reproduce
 Steps to reproduce the behavior:
 
 1. Go to '...'
@@ -17,16 +17,16 @@ Steps to reproduce the behavior:
 3. Scroll down to '....'
 4. See error
 
-**Expected behavior**
+## Expected behavior
 A clear and concise description of what you expected to happen.
 
-**Screenshots**
+## Screenshots
 If applicable, add screenshots to help explain your problem.
 
-**Desktop (please complete the following information):**
+## Environment <!-- (please complete the following information): -->
 
-- OS: [e.g. Windows, Mac, Linux (State distribution)]
-- Version [e.g. 0.10.0-rc1 or 0.9.12]
+- OS: [e.g. Windows, Mac, Linux (State distribution), Android, iOS, Browser]
+- Avalonia-Version: [e.g. 11.x.y or 0.10.x]
 
-**Additional context**
+## Additional context
 Add any other context about the problem here.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -6,14 +6,14 @@ labels: enhancement
 assignees: ''
 ---
 
-**Is your feature request related to a problem? Please describe.**
+## 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**
+## Describe the solution you'd like
 A clear and concise description of what you want to happen.
 
-**Describe alternatives you've considered**
+## Describe alternatives you've considered
 A clear and concise description of any alternative solutions or features you've considered.
 
-**Additional context**
+## Additional context
 Add any other context or screenshots about the feature request here.