Add abandon warning

Author: szepeviktor

README.md

@@ -1,3 +1,12 @@
+> [!IMPORTANT]
+> Hello everyone! This is Viktor who runs the php-stubs organization. I am planning to stop contributing to the WordPress ecosystem because it is extremely difficult and I do not earn (min) €100/month.
+
+Please support my work to avoid abandoning this package.
+
+[![Sponsor](https://github.com/szepeviktor/.github/raw/master/.github/assets/github-like-sponsor-button.svg)](https://github.com/sponsors/php-stubs)
+
+Thank you!
+
 # WordPress Stubs
 
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