✨ NEW: Consider adding dropdown with useful Python links

[mbercx]

trafficstars

One potential issue is that some of the participants might not have a lot of Python experience. Rather than write them off, I want to give them a list of resources to consult two weeks before the tutorial that they can use to get their Python know-how up to snuff to what's needed for AiiDA.

These resources can be repeated at the top of each section, focussing on the links that are most pertinent to that section (and not repeating too much). I think giving them a little hand this way might rope in users that just haven't learned Python yet.

[mbercx]

Also see @ramirezfranciscof's comment in https://github.com/aiidateam/aiida-tutorials/issues/329#issue-907362621

[mbercx]

Note: we currently add useful Python links to the margins as described in the wiki. Will try to give sections a pass and add some more of these before closing this issue.