Add a new type of content to the navigation bar.

[imheavi]

Is your suggested enhancement related to a problem? Please describe.

With mods like TaCZ and Point Blank, that use content packs, we need a new type of content to allow the launcher to install these packs, and make give them a proper listing.

Describe the solution you'd like

A new button on the navigation bar to show content packs for different mods.

Describe alternatives you've considered

none.

Additional context