feat: implement fork-friendly CI/CD with opt-in mechanism (#476)

- CI/CD disabled by default in forks to conserve resources
- Users can enable via ENABLE_CI_IN_FORK repository variable
- Added comprehensive Fork Guide documentation
- Updated README with Contributing section
- Created automation script for future implementations

Benefits:
- Saves GitHub Actions minutes across 1,600+ forks
- Cleaner fork experience for contributors
- Full control for fork owners
- PR validation still runs automatically

BREAKING CHANGE: CI/CD no longer runs automatically in forks.
Fork owners must set ENABLE_CI_IN_FORK=true to enable workflows.

Co-authored-by: Brian <bmadcode@gmail.com>
Co-authored-by: PinkyD <paulbeanjr@gmail.com>

.github/workflows/manual-release.yaml

@@ -20,6 +20,7 @@ permissions:
 jobs:
   release:
     runs-on: ubuntu-latest
+    if: github.event.repository.fork != true || vars.ENABLE_CI_IN_FORK == 'true'
     steps:
       - name: Checkout
         uses: actions/checkout@v4