What is says on the tin.
This has got more to do with making `clippy` slightly more *quiet* than it does with changing anything that might greatly impact readability or performance.
that said, deriving `Default` for a couple of structs is a nice easy win
This PR is part of the issue #3492.
# Objective
- Add and update the bevy_tasks documentation to achieve a 100% documentation coverage (sans `prelude` module)
- Add the #![warn(missing_docs)] lint to keep the documentation coverage for the future.
## Solution
- Add and update the bevy_math documentation.
- Add the #![warn(missing_docs)] lint.
- Added doctest wherever there should be in the missing docs.
#3457 adds the `doc_markdown` clippy lint, which checks doc comments to make sure code identifiers are escaped with backticks. This causes a lot of lint errors, so this is one of a number of PR's that will fix those lint errors one crate at a time.
This PR fixes lints in the `bevy_tasks` crate.
