Fix code quality issues

- Update composer.lock file to match composer.json
- Fix Markdown formatting in README.md
- Fix phpcs.xml argument syntax
- Fix phpstan.neon excludePaths syntax

phpcs.xml

@@ -12,7 +12,7 @@
     <exclude-pattern>*/tests/*</exclude-pattern>
     <exclude-pattern>libs/</exclude-pattern>
 
-    <arg value="sp" />
+    <arg value="-sp" />
     <arg name="extensions" value="php" />
     <arg name="basepath" value="." />
     <arg name="parallel" value="8" />