[python3] README: Updated fork description.
[python3] README: Updated fork description.

--HG--
extra : transplant_source : cu%C5%7C%DD%ECJ%8Ap%B2%D9%D2%22T%F3%E0%3E%E2%F8%11

userzimmermann/robotframework,userzimmermann/robotframework,userzimmermann/robotframework,userzimmermann/robotframework,userzimmermann/robotframework