Added documentation to `three_dimensions`

[alembcke]

Overview: What does this pull request change?

Add documentation to three_dimensions.

Motivation and Explanation: Why and how do your changes improve the library?

More thorough and complete documentation for three_dimensions.

Links to added or changed documentation pages

https://manimce--2915.org.readthedocs.build/en/2915/reference/manim.mobject.three_d.three_dimensions.html

Further Information and Comments

Sorry for the sloppy commit history.

Reviewer Checklist

• [ ] The PR title is descriptive enough for the changelog, and the PR is labeled correctly
• [ ] If applicable: newly added non-private functions and classes have a docstring including a short summary and a PARAMETERS section
• [ ] If applicable: newly added functions and classes are tested

[alembcke]

The convention is that the "Parameters" section should be before the "Examples" section, but this wasn't followed on some of the docstrings. So I updated that with another commit.