Plugin support

[otter501]

The problem

I want to easily manage my server plugins and ferium seem as if it need only a few mods to make plugin support

My solutions

Add a type of profile for plugins and add a ferium plugin add command

[theRookieCoder]

I will probably add this together with multiple project types support (#141), but I'll keep this issue separate.

[deniz-blue]

hi! i was lurking. maybe this project might be useful for you

(ps. i didnt know ferium existed before i made that lmao)