Update feature_request.md (#529)

* Update feature_request.md

Change to use markdown

* Code review

Author: cnovak

.github/ISSUE_TEMPLATE/feature_request.md

@@ -7,14 +7,14 @@ 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 would like
 A clear and concise description of what you want to happen.
 
-**Describe alternatives you've considered**
+## Describe alternatives you have 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.