Consider showing updates for mods also since many addons depend on them

Many addons depend on mods like [nampower](https://gitea.com/avitasia/nampower/releases), [unitxp_sp3](https://codeberg.org/konaka/UnitXP_SP3/releases) and [superwow](https://github.com/balakethelock/SuperWoW/releases).

Consider being able to add a repository for each mod to check for updates (releases), if downloading and installing them is not within the scope of snapjaw.