Add demo options from new LC Python lesson

[ndporter]

How could the content be improved?

Add teaching demo options from Library Carpentry Python now that a stable release is part of the official curriculum.

Which part of the content does your suggestion apply to?

https://carpentries.github.io/instructor-training/demo_lessons.html#lc

[ndporter]

@tobyhodges you may want to check on the TidyData lesson too. I've been teaching that for at least 2 years and it hasn't changed much (and is pretty polished) but still shows as unstable in the demos list.