Increased Clarity for Pro Features in Documentation

[TingleyWJ]

Quick Description

Add a stamp, image, or otherwise clear marker at the top of each page of documentation as to whether the specified class, interface, or other is Free or Pro.

For Feature Requests

Entire documentation would benefit from having visual Free/Pro clarification at the top of each page.

Some current examples where it would help are:
Timer Class: Pro, but missing the remark stating that it was Pro, so it isn't known (bug, but pointed out in discord).
Plugin.BadWorldFilter: Pro, but marked at the bottom of the page in plain text as Pro only. Not immediately visible.

[JamJar00]

Thanks TingleyWJ!

I'll look into how I can make this more obvious, their should at least be a standard place for notices so I'll get that done for the next version.

Jamie

[JamJar00]

The next version should have these a bit more standardized, they'll all be in the remarks section which isn't ideal but should be a bit bolder (I can't make them standout brilliantly because of the software that generates the docs).

I'll leave this open so I remember to look into this if I switch to DocFX instead!

[JamJar00]

@TingleyWJ I've transferred this to the new documentation repository. Hopefully, we can do a bit more about this now we're on DocFx!