Present mod-specific collection instructions to the user

[Pickysaurus]

Mods in collections can have instructions attached to them. We should have a way to display this to the user.

https://modding.wiki/en/nexusmods/collections/create/mod-options#instructions

Note: Optional mods display the instruction before install so the user can see why it was marked optional. Required mods will show the instructions during/after install as this may help them make the correct choices in a FOMOD.