Add feature request template (#42)

.github/ISSUE_TEMPLATE/feature-request-issue-template.md

@@ -0,0 +1,30 @@
+---
+name: Feature Request Issue Template
+about: Suggest a new feature for this project
+title: "[Feature]"
+labels: ''
+assignees: ''
+
+---
+
+## Checklist  
+
+- [ ] This feature will maintain backward compatibility with the current APIs in `realhf/api/`. If not, please raise a refactor issue first.  
+
+## Background  
+
+Is your feature request related to an enhancement or a new use case? Please describe.  
+
+**Example 1:**  
+"I'd like to support zero-bubble pipeline parallelism, as it significantly improves training throughput."  
+
+**Example 2:**  
+"I'd like to add expert parallelism to enable efficient training of large MoE models."  
+
+## Potential Solution  
+
+A clear and concise description of the potential implementation or how similar features are handled in other frameworks.  
+
+## Additional Information  
+
+(Add any relevant context, references, or supporting data here.)