source engine easter egg option

pack/unsup.toml

@@ -40,6 +40,18 @@ id = "ambient-sounds_on"
 [[flavor_groups.ambient-sounds.choices]]
 id = "ambient-sounds_off"
 
+
+[flavor_groups.half-life]
+name = "Half Life 2"
+id="half-life"
+description = "Half-Life 2 is a 2004 first-person shooter game developed and published by Valve Corporation. It was published for Windows on Valve's digital distribution service, Steam. Like the original Half-Life (1998), Half-Life 2 is played from a first-person perspective, combining combat, puzzles, and storytelling. It adds features such as vehicles and physics-based gameplay. The player controls Gordon Freeman, who joins a resistance effort to liberate Earth from the alien Combine empire."
+side = "client"
+
+[[flavor_groups.half-life.choices]]
+id = "half-life_off"
+[[flavor_groups.half-life.choices]]
+id = "half-life_on"
+
 [flavor_groups.aliasing]
 name = "Anti-aliasing"
 description = "Smoothes out the jagged edges of blocks, improving clarity and reducing noise when viewing far off objects."
@@ -83,6 +95,9 @@ flavors = ["fancy"]
 [metafile.charmonium]
 flavors = ["ambient-sounds_on"]
 
+[metafile.source-engine-sounds]
+flavors = ["half-life_on"]
+
 [metafile.dirtyaliasing]
 flavors = ["dirty"]
 [metafile.qdaa]