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/smolblog/oauth2-twitter/.phpcs.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<ruleset name="Smolblog League Project" namespace="Smolblog\League">
+	<description>Coding standards for Smolblog-maintained PHPLeague-compatible packages.</description>
+
+	<file>./src</file>
+
+	<arg name="extensions" value="php"/>
+	<arg name="tab-width" value="2"/>
+	<arg name="colors"/>
+
+	<ini name="memory_limit" value="64M"/>
+
+	<autoload>./vendor/autoload.php</autoload>
+
+	<!-- Use PSR-2 as our base -->
+	<rule ref="PSR2"/>
+</ruleset>