Pytroll package overview out of date: lists archived repositories as current and lists all as Python 2 compatible

[gerritholl]

The PyTroll (sic) package overview is out of date on several accounts:

• It spells PyTroll rather than Pytroll
• It claims that "All packages are Python 2.7 compatible"
• It lists several packages as current, but clicking through results in a github project that is archived. Examples are trollflow and trollflow-sat. I did not check all. Probably there should be a section near the bottom for "obsolete/archived/historical packages" which would include trollduction, trollflow, trollflow-sat, mipp, mpop, and maybe others.