* wip: update props api
* feat(#139, #309): enable new props api
* chore: migrate examples to new props API
* docs: update syntax guide for new props API
* chore: update examples to new props API
* chore: update docs to new Props API
* fix: hide __astroInternal from `Astro.props` consumers
* chore: remove scratchpad file
* chore: fix script error
* test: fix failing collection tests
* fix: set __astroInternal to `enumerable: false`
* chore: add changeset
* feat: warn users using old props api
