Hook fixes for L, M, N, and O
Created by: agh1
Hit the middle of the alphabet on updating the hook docs. Some things I standardized:
- declaring the type of the param, followed by the param name, then a hyphen, then the description
- putting code blocks in
```php
rather than indents - stripping out references to behavior in pre-4.6 versions
I also did minor grammatical fixes and made sure the code was in proper style.