chore: open-source readiness — LICENSE, CONTRIBUTING, templates, package metadata

- Add MIT LICENSE
- Add CONTRIBUTING.md with setup, conventions, PR workflow
- Add GitHub issue/PR templates
- Add repository/homepage/bugs/license to all package.json files
- Add Install section to README before Quick Start

Fixes #510

小橘 🍊（NEKO Team）

packages/workflow-moderator/package.json

@@ -27,5 +27,15 @@
   },
   "publishConfig": {
     "access": "public"
-  }
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/shazhou-ww/uncaged-workflow.git",
+    "directory": "packages/workflow-moderator"
+  },
+  "homepage": "https://github.com/shazhou-ww/uncaged-workflow#readme",
+  "bugs": {
+    "url": "https://github.com/shazhou-ww/uncaged-workflow/issues"
+  },
+  "license": "MIT"
 }