Add MIT license, contributing guidelines, update for public repo

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: ejntaylor

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Patchstack
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -12,14 +12,14 @@ PHP's `version_compare('3.5', '3.41')` returns `-1` (meaning 3.5 < 3.41), becaus
 composer require patchstack/version-compare
 ```
 
-For private repo access, add the VCS repository to your `composer.json`:
+Since this package is not on Packagist, add the VCS repository to your `composer.json`:
 
 ```json
 {
     "repositories": [
         {
             "type": "vcs",
-            "url": "git@github.com:patchstack/version-compare.git"
+            "url": "https://github.com/patchstack/version-compare.git"
         }
     ]
 }
@@ -125,6 +125,21 @@ $checker->execute('9.x-3.4', '<= 8.x-3.5');  // false (different major)
 composer test
 ```
 
+## Contributing
+
+This package is maintained by the Patchstack engineering team. Changes should be made via pull request with tests.
+
+When adding new version format support:
+1. Add test cases covering the new format in the relevant test file
+2. Ensure all existing tests still pass
+3. Update this README's "Supported Version Formats" table
+
+Version bumps follow semver. Breaking changes to the public API require a major version bump since multiple codebases depend on `^1.0`.
+
+## License
+
+MIT - see [LICENSE](LICENSE)
+
 ## Requirements
 
 - PHP 8.1+

composer.json

@@ -2,7 +2,7 @@
     "name": "patchstack/version-compare",
     "description": "Framework-agnostic version comparison logic for vulnerability checking",
     "type": "library",
-    "license": "proprietary",
+    "license": "MIT",
     "require": {
         "php": "^8.1"
     },