Make a status badge that includes all versions here

[cjrh]

https://pypi.org/project/pybadges/

We want to make a badge that says python | 3.6 | 3.7 | 3.8 | 3.9 | pypy3

Because the standard status badge doesn't add pypy. Other projects are including this in an "implementation" badge, e.g.:

https://raw.githubusercontent.com/pypa/virtualenv/master/README.md

[cjrh]

I've just split this between versions and implementations, and it's fine.