Yes, yes it does. There is a menu item labeled 'Add A Non-Steam Game To My Library', after adding you can also use steam's compatibility tools (Proton, or DOSB

Yes, yes it does. There is a menu item labeled 'Add A Non-Steam Game To My Library', after adding you can also use steam's compatibility tools (Proton, or DOSBox or whatever custom compatibility tools) with the games as well.