CHANGELOG: Highlight the subtlety of the Function Call breaking change

CHANGELOG.md

@@ -30,7 +30,7 @@ to run a pre-compiled script in new contexts.
 - Removed error return value from NewContext which never fails
 - Removed error return value from Context.Isolate() which never fails
 - Removed error return value from NewObjectTemplate and NewFunctionTemplate. Panic if given a nil argument.
-- Function Call accepts receiver as first argument.
+- Function Call accepts receiver as first argument. This **subtle breaking change** will compile old code but interpret the first argument as the receiver. Use `Undefined` to prepend an argument to fix old Call use.
 - Removed Windows support until its build issues are addressed.
 - Upgrade to V8 9.6.180.12