shop.yml configurable as upgrades2.yml.

[MrShadow-X]

Is your feature request related to a problem? Please describe.

• Not a problem, just adding feature to make shop.yml configurable as upgrades2.yml

Describe the solution you'd like.

• Change shop.yml to be like upgrades2.yml, so you can add own items, configurate and put them where you like.

Describe alternatives you've considered

• No idea. Maybe reworking gui creation, so it'll be more user-friendly, idk.

Additional context

• What I mean by all of this is adding something like this from upgrades to shop: so the output will be:

Right now you can only make custom categories, and place custom items in them.

(So for example: make ability to place custom items in these x marked slots that can be separators or sth.)