Update README.md

Author: jdkandersson

README.md

@@ -1649,6 +1649,5 @@ Section information is extracted using the following algorithm:
 ## Future Ideas:
 
 - Check that argument, exceptions and attributes have non-empty description.
-- Check that arguments, exceptions and attributes are only documented once.
 - Check that arguments, exceptions and attributes have meaningful descriptions.
 - Check other other PEP257 conventions