Prepare packages for publishing

[samchesney]

This will require multiple steps:

• Updates to the package configurations such that they meet the requirements for crates.io:
  • Preparation for initial release to crates.io #97
  • chore: allow publishing to crates.io #99
  • Release prep #104
  • Update dependencies and tooling #105
  • Fix developer guide build #106
  • Add README for every package to be published #107
• Release notes generated by release-plz:
  • chore: release #100
• Release created with release-plz (publishing the packages to both GitHub and crates.io).