Follow-up to #31925, `<member />` tags just before `</members>` would cause
a parsing issue, and we'd never notice that we're no longer parsing members.
Also added space before closing `/>`.
Setters and getters have been hidden from the documentation when the matching
properties have been exposed, but some of them are parametric and require the
name or index of a given parameter to be used. So they need to be properly
documented with the type and name of the arguments they take.
For example, CPUParticles' `set_param(Parameter param, float value)`.
- Document a few more properties and methods
- Add more information to many classes
- Fix lots of typos and gramar mistakes
- Use [code] tags for parameters consistently
- Use [b] and [i] tags consistently
- Put "Warning:" and "Note:" on their own line to be more visible,
and make them always bold
- Tweak formatting in code examples to be more readable
- Use double quotes consistently
- Add more links to third-party technologies
