Migration rules for font curves

[leagrdv]

The goal of this ticket is to create migration rules for the changing of font curves.

Tasks

• Create a migration rule in our ESLint package that automatically replaces:
  • font-curve-tiny -> fs-9
  • font-curve-small -> fs-7
  • font-curve-regular -> fs-6
  • font-curve-bigger-regular -> fs-5
  • font-curve-medium -> fs-4
  • font-curve-large -> fs-3
  • font-curve-big -> fs-1
• Document the migration rule in the ESLint package
• Add tests for the rule
• Add an entry in the migration guide (currently, there is only an entry for the font sizes, not the curves) with the auto-migration tag
• Replace the class in our own codebase

[leagrdv]

Dev roundtable question

I've added the migration rules for the font curves, which are not 100% identical but still pretty similar.

We used to have 11 static font sizes classes as well, and some of them would have an equivalent but not all of them. Do we still want to create migration rules for them or not? If so, only the exactly identical or also the similar ones?

Previous font sizes:
12, 14, 16, 18, 20, 24, 28, 32, 40, 48, 56

Current font curves:

[gfellerph]

• font-size48 and 56 are only used to size icons by 3 projects
• Should we offer automigrations specifically for icons that were being sized with font-size-x? If yes, to what?
• To not break the layout, it would make sense to use static width and height, @leagrdv can you create a ticket for that?
• for spacing utilities smaller-large and bigger-giant we don't have direct mappings and offer auto-migrations to the closest we have. We're including a not for those two that they should be reviewed carefully before accepting the auto-migration

[leagrdv]

Ticket created for the font sizes #6156