Add Urho3D Engine

[MichaelHinrichs]

SteamDB app page links to a few games using this

https://steamdb.info/app/375220/ https://steamdb.info/app/450360/ https://steamdb.info/app/694610/ https://steamdb.info/app/793620/ https://steamdb.info/app/845630/ https://steamdb.info/app/927840/ https://steamdb.info/app/1203310/ https://steamdb.info/app/1204550/ https://steamdb.info/app/1213450/

Brief explanation of the change

Add Urho3D engine. Find the shader Urho2D.glsl.

[MichaelHinrichs]

Pull this.

[SteamDB-Tracker]

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

Changed technologies: Engine.Urho

These apps now match: (8) 375220 694610 793620 845630 927840 1203310 1204550 1213450

Please confirm that all these changed apps are correct.