command-line-reference options should be grouped by DocumentationCategory, not command

The current generated option documentation groups options by command. For options that are inherited through the command hierarchy (`test` inherits from `build`, etc), we don't list the options twice, but for options lists that are included in many commands explicitely, we list the option multiple times.

Instead of this cat and mouse game where, to find out if an option applies to a command, you see what command it's listed under and what other commands inherit from it, the options should just list the commands to which they apply:

```
--

Applies to commands :
```

At this point, each option would only need to be listed once, which means we could link to the option documentation clearly from elsewhere in the docs.