plotting clean-up tasks

[claireyung]

• Fix labels - MITgcm BAS Coupled (no V3) and MOM6-LAYER (add LAYER). In some places long label is hard to read - fix with double lines. ROMSUTAS -> ROMS
• Add TYP plots of circulation and many other metrics for completeness
• vertical coordinate description labels (z,s etc) are on Figs 1-4: they should probably be on at least the BL figures
• Supplementary videos
• Clean up the github (resolve issues but point to the discussions somewhere) and archive superfluous or old notebooks