docs: Fix README link.

Author: drupol

README.md

@@ -3,7 +3,7 @@
 [![GitHub Workflow Status][github workflow status]][2]
 [![Scrutinizer code quality][code quality]][3]
 [![Type Coverage][type coverage]][4] [![Code Coverage][code coverage]][3]
-[![License][license]][1] [![Donate!][donate github]][5]
+[![License][license]][1] [![Donate!][donate github]][github sponsors link]
 
 # PHPUnit Iterable Assertions