PHP Psalm Specify current contributing guidelines

GitOrigin-RevId: a2cfcdfa40fc6f2ce9a9ae0b7aa58861ca914063

Author: wbars

CONTRIBUTING.md

@@ -0,0 +1,7 @@
+# Contributing
+
+If you are introducing a user-visible change, please make sure to:
+- create the corresponding issue first in [our tracker](https://youtrack.jetbrains.com/newIssue?project=WI)
+- comment about intention to start a work on the fix
+- cover the change with a test with the implementation
+- mention issue id in pull request

README.md

@@ -15,8 +15,4 @@ This plugin adds dedicated functionality for [Psalm](https://psalm.dev/) to [Php
 **Psalm annotations support**
 
 - Existing PhpStorm code analysis features are aware of Psalm-specific annotations
-- New Psalm-related inspections
-  
-# Contributing
-
-If you are introducing a user-visible change, please make sure to create the corresponding issue first, comment about intention to start a work on the fix and cover the change with a test with the implementation.
+- New Psalm-related inspections