*sigh*
People download things these days without even knowing what they are...
The Resource Pack reskins a lot of the entities in hammer to be more easy to use, for example info_player_teamspawns and a lot of the gameplay entities. It also provides
prefabs to make some tedious parts of mapping easier, such as doors and path_tracks. Indeed, it does also provide the gametype and prop libraries. The updated version can be found
here.
-> Reset Game Configs = Source SDK -> 'Refresh SDK content' + 'Reset Game Configurations'.