chore: bump version to v2.2.0 and update documentation

Version updates:
- marketplace.json metadata.version: 2.0.0 → 2.2.0
- marketplace.json projman version: 2.0.0 → 2.2.0
- plugins/projman/plugin.json version: 2.0.0 → 2.2.0

Documentation updates:
- CHANGELOG.md: Changed [Unreleased] to [2.2.0] - 2026-01-20
- README.md: Updated projman version to v2.2.0
- README.md: Added /review and /test-check to commands list
- README.md: Added code-reviewer to agent list
- README.md: Updated Key Features section to v2.2.0
- README.md: Added validate-marketplace.sh to structure
- plugins/projman/README.md: Updated title to v2.2.0
- plugins/projman/README.md: Updated version changelog

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

plugins/projman/.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "projman",
-  "version": "2.0.0",
+  "version": "2.2.0",
   "description": "Sprint planning and project management with Gitea integration",
   "author": {
     "name": "Leo Miranda",