Filter out small documentation improvements in changelogs

> it's kinda annoying that the bevy changelog includes all the tiny docs PRs
>
> i want to know what changed in the ECS, but much of the A-ECS changelog is stuff like "clarify the purpose of commands in docs" (which changes 1 word), "fix typo in comment", ...
>
> From @inodentry on [Discord](https://discord.com/channels/691052431525675048/692572690833473578/1216700801502810152)

Here are a few ideas:

- Label PRs with something like `Changelog-Irrelevant` and filter them out in `generate-release`
- They can either be removed entirely, or added to their own section.
- Remove these small changes retroactively, after the initial changelog has been released
- Suggested on [Discord](https://discord.com/channels/691052431525675048/692572690833473578/1216701657350406215)
- Potentially link to the Github diff, such as [`0.12.0...0.13.0`](https://github.com/bevyengine/bevy/compare/release-0.12.0...release-0.13.0), for a _full_ full changelog