Steam ROM Manager
Steam ROM Manager is a super flexible tool for adding non-Steam games to steam in bulk and managing their artwork assets.
Summary
Steam ROM Manager is a super flexible tool for adding non-Steam games to steam in bulk and managing their artwork assets. Added games could be ROMs for emulators, games from other stores such as Epic or GOG, or even not games at all. Have you always wanted your notes from junior year as a category in steam? If so that's pretty weird! But now it's possible.
- Steam ROM Manager README
For an overview of how it works go here. There is plenty of documentation available in the app's built in FAQ, and if you need further help there are expert users to be found on the SGDB discord under the Steam ROM Manager category and the Steam ROM Manager subreddit. Check out the releases page for compiled downloads.