Add Foundation Engine

[MichaelHinrichs]

SteamDB app page links to a few games using this

https://steamdb.info/app/203160/ https://steamdb.info/app/289690/ https://steamdb.info/app/391220/ https://steamdb.info/app/750920/ https://steamdb.info/app/974630/ https://steamdb.info/app/997070/

Brief explanation of the change

Find bigfile.000.tiger, in Foundation games.

[SteamDB-Tracker]

After running changed rules in this pull request (this bot only tests rules.ini changes):

Changed technologies: Engine.Foundation

These apps now match: (7) 203160 289690 391220 750920 974630 997070 1358820

Please confirm that all these changed apps are correct.

[Lifeismana]

not used by enough apps