Add region ignore with gmask

[OneLiteFeather]

Overview

Some players do not know how to exclude a part of their build so that only a part is changed This was raised in https://github.com/IntellectualSites/documentation/issues/67

Description

Add a step-by-step tutorial how to do it

### Submitter Checklist
- [x] Make sure you are opening from a topic branch (**/feature/fix/docs/ branch** (right side)) and not your main branch.
- [x] Ensure that the pull request title represents the desired changelog entry.
- [x] New public fields and methods are annotated with `@since TODO`.
- [x] I read and followed the [contribution guidelines](https://github.com/IntellectualSites/.github/blob/main/CONTRIBUTING.md).

[NotMyFault]

Please compress the images, i.e. https://compressor.io/

[OneLiteFeather]

Please compress the images, i.e. https://compressor.io/

Done, hopefully we can minimize the storage footprint with that

[RedstoneFuture]

I think this is very rudimentary. We actually show separate full documentation in the planned mask instructions.

EDIT: Now I see "/advanced-commands" is a new category, okay. Perhaps we could also call it "Start-up Tutorial".

[OneLiteFeather]

EDIT: Now I see "/advanced-commands" is a new category, okay. Perhaps we could also call it "Start-up Tutorial".

I had the idea to name it this way to allow adding the special and more in depth commands from the community which would be lost in the start up tutorials. For example, there are very advance / special commands on the guide from zeranny and eztak I have allowance to add and mention, but very helpful for advanced builders. This documentation on the PR is also something you rarely need because it is special.

[TheMeinerLP]

Whats the status here ?

[NotMyFault]

@SirYwell Do you want to take another look, please?