bevy-releasability

CI jobs to help check the release readiness of the Bevy project:

• check ownership of crates
• check crate build with default feature, all features, no default features
• check crate build for wasm32-unknown-unknown and aarch64-apple-ios
• check each top level feature individually
• build doc with example scrapping for each example individually
• release Bevy to a private repo to test the release process