Add Symfony Deprecation Contracts package

- Created CHANGELOG.md to maintain version history.
- Added README.md with usage instructions for the trigger_deprecation() function.
- Initialized composer.json for the Symfony Deprecation Contracts library, specifying dependencies and autoloading.

modules/pshowsso/deps/league/oauth2-facebook/.github/workflows/static-analysis.yaml

@@ -0,0 +1,23 @@
+name: Code style
+
+on:
+    pull_request:
+    push:
+        branches: [ master ]
+
+jobs:
+    php-cs-fixer:
+        name: PHP-CodeSniffer
+        runs-on: ubuntu-latest
+        steps:
+            - name: Checkout
+              uses: actions/checkout@v2
+
+            - name: Setup PHP
+              uses: shivammathur/setup-php@v2
+
+            - name: Install dependencies
+              run: composer install
+
+            - name: Run script
+              run: ./vendor/bin/phpcs src --standard=psr12 -sp