`README.md`

[jorenham]

It should at least have (n no particular order):

• installation instructions (✨: create HasArrayNamepace #17)
• references to the main repo
• an answer to questions like:
  • what's the problem that xpt solves?
    • why does that matter?
  • should I use it?
  • how can I use it?
  • does it support ?
  • can I use with with array-api 20XX.12.1?
  • will understand it?
  • how can I contribute?
  • what's up with the sparkly stuff? my eyes hurt!
• badges, emojis, glitter, rainbows, unicorns etc.