Add troubleshooting how-to to zk-docs (#99)

## Summary
- Add the troubleshooting how-to guide to the zk-docs script output
- Placed after how-to/index.md to group how-to content together

## Deployment and Testing
- [x] Verified script runs successfully with `mise run zk-docs`
- [x] Changelog fragment added

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

Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/99

mise-tasks/zk-docs

@@ -10,6 +10,7 @@ FILES=(
     "$DOCS_DIR/tutorials/ai-assistance-guide.md"
     "$DOCS_DIR/reference/index.md"
     "$DOCS_DIR/how-to/index.md"
+    "$DOCS_DIR/how-to/troubleshooting.md"
     "$DOCS_DIR/explanation/architecture.md"
     "$DOCS_DIR/tutorials/index.md"
 )