Short vignettes on:

• Pitch plotting basics (most of what's in the README at the moment)
• Example with statsbomb(?) data
• Pitch dimensions
  • Which ones are available? what do they look like?
  • Defining and using a custom pitch spec (even if it's just changing one attribute)
  • Converting between pitch specs
• Customising pitch appearance (size, alpha, etc)

This enables us to make the README a bit more high-level:

• How to install ggsoccer
• How to use it in a "real" example
• Additional features/etc
  • Links to relevant vignettes probably fit well here
• Package "philosophy" (less pretentious term pls)
• Links to alternative options (and options in other langs)