feat: Add GitHub issue and PR templates (gt-599nf)

Add .github/ISSUE_TEMPLATE/ with bug_report.md and feature_request.md
templates. Add .github/PULL_REQUEST_TEMPLATE.md for PR submissions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,22 @@
+---
+name: Feature Request
+about: Suggest a new feature for Gas Town
+title: ''
+labels: enhancement
+assignees: ''
+---
+
+## Problem Statement
+<!-- What problem does this feature solve? -->
+
+## Proposed Solution
+<!-- Describe the feature you'd like -->
+
+## Alternatives Considered
+<!-- Any alternative solutions or features you've considered -->
+
+## Use Case
+<!-- How would you use this feature? -->
+
+## Additional Context
+<!-- Any other context, mockups, or examples -->