[Catalog] Add visuals to games catalog

[edwardchalstrey1]

This feature request is for...

PyGambit

Requested enahancement or feature

In #753 we have added the Catalog of games. Each game is listed in a table on the "Catalog of games" page of the docs.
To help people reading the documentation understand the games, we could add visuals of the games to these pages.

• Might be worth using SVG rather than PNG for this, so would need to complete [Good first issue]: Add generate_svg function draw_tree#40 and do a release Can use TikZ directly
• Draw all the EFG games in the catalog with draw_tree
• Ensure images are not created and added to Makefile, but are generated when building the docs
• Can we get a full screen button for the images?
• Add dowload links for tex, png and pdf
  • Need to fix PNG in draw_tree to run locally - however this should already be fine on rtd build
• Open and complete any issues for draw_tree that need to be fixed for a large set of the Catalog games to look good
• Release new draw_tree version and use it in Gambit: 0.4 https://github.com/gambitproject/draw_tree/issues?q=is%3Aissue%20state%3Aopen%20milestone%3A0.4.0
• Can we also visualise NFGs via printing the table in the docstring? Or can we just visualise them as EFGs?
• Make sure coded games get an efg/nfg download too
• Make sure nfg has description included too
• Should probably save images (including tikz) to avoid regenerating them whenever the update script is run, otherwise this will take forever for a large catalog
• Add download for .ef
• Document how the update script changes now image generation added
• Open a separate PR to main adding pip install . as a step before running the update script in the catalog developer docs
  • Ensure that the catalog update script generates the images for a new game, even if --build flag not included
• Might need to separate the --build flag for updating the makefile from a flag for generating all images, since we need to use the build flag when adding a new game, but might not want to re-generate all games (indeed the image files will definitely be different)