docs: add RFC commands to README and bump projman version

- Add 5 RFC commands to projman Commands line in README.md
- Bump projman version 3.3.0 → 3.4.0 in marketplace.json

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

README.md

@@ -19,7 +19,7 @@ AI-guided sprint planning with full Gitea integration. Transforms a proven 15-sp
 - Branch-aware security (development/staging/production)
 - Pre-sprint-close code quality review and test verification
 
-**Commands:** `/sprint-plan`, `/sprint-start`, `/sprint-status`, `/sprint-close`, `/labels-sync`, `/setup`, `/review`, `/test`, `/debug`, `/suggest-version`, `/proposal-status`, `/clear-cache`
+**Commands:** `/sprint-plan`, `/sprint-start`, `/sprint-status`, `/sprint-close`, `/labels-sync`, `/setup`, `/review`, `/test`, `/debug`, `/suggest-version`, `/proposal-status`, `/clear-cache`, `/rfc-create`, `/rfc-list`, `/rfc-review`, `/rfc-approve`, `/rfc-reject`
 
 #### [git-flow](./plugins/git-flow) *NEW in v3.0.0*
 **Git Workflow Automation**