API Documentation cleanup

[zachcran]

Is this pull request associated with an issue(s)? No.

Description Now that API documentation is online, it needs to be cleaned up and made consistent.

TODOs

• [x] Ensure that the "Example Usage" and "Error Checking" sections always appear in the same order.
• [x] Move all brief descriptions to the second line of the block comment. This frees the first line (line containing #[[[) for special specifiers like @module.
• [x] Move code snippets into a .. code-block:: so they render properly.
• [x] Proofread documentation.
• [x] Figure out how to render the :var VARIABLE: and :vartype VARIABLE: commands properly.
• [x] Configure CMinx to remove prefixes from function, macro, and member function parameters.
• [x] Manually remove the parameter prefixes defined in the docstrings.

[zachcran]

I'll see if I can figure out the module doccomments, at least locally, as well as see if I can fix that warning. Thanks again!

[zachcran]

@AutonomicPerfectionist @ryanmrichard Are module doccomments expected to be at the top of each file, or just the files including all of the files in a subdirectory (for example, cmake/cmakepp_lang/cmakepp_lang.cmake and cmake/cmakepp_lang/algorithm/algorithm.cmake)?

[AutonomicPerfectionist]

Top of the file you want to document, before any commands like include_guard()

So you can do both: put a module doccomment on the "main" files that include the others, saying what that subdirectory is for, and then have more specific doccomments for each of the individual modules