## Objective
Fixes https://github.com/bevyengine/bevy/issues/6063
## Solution
- Use `then_some(x)` instead of `then( || x)`.
- Updated error logs from `bevy_ecs_compile_fail_tests`.
## Migration Guide
From Rust 1.63 to 1.64, a new Clippy error was added; now one should use `then_some(x)` instead of `then( || x)`.
# Objective
- Have information about examples only in one place that can be used for the repo and for the website (and remove the need to keep a list of example to build for wasm in the website 75acb73040/generate-wasm-examples/generate_wasm_examples.sh (L92-L99))
## Solution
- Add metadata about examples in `Cargo.toml`
- Build the `examples/README.md` from a template using those metadata. I used tera as the template engine to use the same tech as the website.
- Make CI fail if an example is missing metadata, or if the readme file needs to be updated (the command to update it is displayed in the failed step in CI)
## Remaining To Do
- After the next release with this merged in, the website will be able to be updated to use those metadata too
- I would like to build the examples in wasm and make them available at http://dev-docs.bevyengine.org/ but that will require more design
- https://github.com/bevyengine/bevy-website/issues/299 for other ToDos
Co-authored-by: Readme <github-actions@github.com>
