feat: add configuration files and scripts for project setup ✨

🚀 Breaking Changes:
- Introduced new environment variables for GitLab API integration
- Added validation script for PR checks
- Updated package.json with new scripts for testing and formatting

📝 Details:
- Added .prettierrc and .eslintrc.json for code formatting and linting
- Created .env.example for environment variable setup
- Updated CHANGELOG.md with recent changes
- Added documentation for GitHub secrets setup

.env.example

@@ -0,0 +1,13 @@
+# GitLab API Configuration
+GITLAB_API_URL=https://gitlab.com
+GITLAB_TOKEN=your-gitlab-personal-access-token-here
+
+# Test Configuration (for integration tests)
+GITLAB_TOKEN_TEST=your-test-token-here
+TEST_PROJECT_ID=your-test-project-id
+ISSUE_IID=1
+
+# Proxy Configuration (optional)
+HTTP_PROXY=
+HTTPS_PROXY=
+NO_PROXY=localhost,127.0.0.1