Update docs/annotating_code/supported_annotations.md

Co-authored-by: Bruce Weirdan <[email protected]>

docs/annotating_code/supported_annotations.md

@@ -505,7 +505,7 @@ $counter->count = 5; // This will fail, as it's mutating a property directly
 
 ### `@psalm-require-usage`
 
-Used to annotate a impure functions, which Psalm should require the call to be used.
+Used to annotate an impure function or method the unused result of which Psalm should report.
 
 ```php
 <?php