Make change detection clamping docs more accessible

## How can Bevy's documentation be improved?

For how change detection is currently implemented, there is a far-fetched technical limitation to it. This is already documented in the public constants [`CHECK_TICK_TRESHOLD`] and [`MAX_CHANGE_AGE`], located in `bevy_ecs::change_detection`, but there are some issues with it:

- Those constants are quite hidden, and they only seem public for the doc comments
- The doc comments refer to `check_tick`, which is a private function, therefore confusing for users who don't know about the implementation details.

### Proposed solution

The constants should be made private, and their documentation should be moved to the `bevy_ecs::change_detection` module level. They should also be adapted to be understandable to people who don't know the implementation details of change detection.

Since the module is practically undocumented, having a brief intro of what change detection is in Bevy, and how it can be used (i.e. by using the change detection filters), would be very appreciated, but not strictly necessary.

---

See also

- #3956

[`CHECK_TICK_TRESHOLD`]: https://dev-docs.bevyengine.org/bevy/ecs/change_detection/constant.CHECK_TICK_THRESHOLD.html
[`MAX_CHANGE_AGE`]: https://dev-docs.bevyengine.org/bevy/ecs/change_detection/constant.MAX_CHANGE_AGE.html