Cassini release v1.0.0

This is Cassini release v1.0.0

On top of release branch (mickledore), makes the following changes

• Cherry picks documentation updates from mickeledore-dev based on release testing
• Adds a default "Read the Docs" build configuration
• Adds release notes to documentation
• Final commit creates the release:
  • Pins SHAs for all dependent layers
  • Updates the documentation with the pinned SHAs
  • Sets DISTRO_VERSION to v1.0.0

Notes:

• The cherry-picked commits have already been reviewed
• Release will be tagged automatically when MR merged