DampedSpringJoint2D documentation is incomplete and partially wrong

**Your Godot version:** v4.0.stable.official [92bee43ad]

**Issue description:** Documentation on DampedSpringJoint2Dis not fully correct and also missing some useful information

**URL to the documentation page:**
https://docs.godotengine.org/en/stable/classes/class_dampedspringjoint2d.html

**Note:** I am not a 100% sure what is a bug and what is wrong documentation which I why I filed [this bug](https://github.com/godotengine/godot/issues/74720). I'd be willing to do a PR, but I have to know first what is a bug and what is not.

- **Missing high-level description of intended usage:** There seems to be quite a bit of confusion as can be seen [here](https://www.reddit.com/r/godot/comments/adahg6/how_does_dampenedspringjoint2d_work/), [here](https://www.reddit.com/r/godot/comments/y2dbol/is_dampedspringjoint2d_just_a_pain_to_use_or_am_i/) and [here](https://www.reddit.com/r/godot/comments/afe8ix/dynamically_instancing_joints/) – I documented [my misconceptions here](https://github.com/godotengine/godot/issues/74720#issuecomment-1483807127) which might help enhancing the documentation
- **stiffness:** Missing information that the value is between 0.1 and 64
- **rest_length:** Missing description of behaviour that if set to 0, it equals to `length` as investigated [here](https://github.com/godotengine/godot/issues/74720#issuecomment-1483804001) (`0` instead of e.g. `-1` for this behavior is also misleading/unintuitive as `0` could be a desired rest length)
- **length:** The documentation states "The spring joint's maximum length" which [does not seem to be true](https://github.com/godotengine/godot/issues/74720)
- **bias:** Technically belongs to Joint2D but in neither context I understand what it means
- **stiffness + damping:** I am not a 100% sure how the 2 values interplay: A high stiffness would equal a stick, a low one very flexible rope I think. How to damping affects that behaviour I am not sure.

I love Godot, so I hope we can figure this out / enhance this :)