Updated README

ondrejmirtes · ondrejmirtes · commit 3bfc4e873b4e · 2018-12-08T23:42:39.000+01:00
diff --git a/README.md b/README.md
@@ -22,6 +22,7 @@
 * Require parameter and return typehints for functions and methods (either native or phpDocs)
 * Correct case for referenced and called function names.
 * Correct case for inherited and implemented method names.
+* Contravariance for parameter types and covariance for return types in inherited methods
 
 Additional rules are coming in subsequent releases!
 
