Updated README.md.

README.md

@@ -5,8 +5,9 @@ license: unknown
 Compiled from several different sets of songs:
 - (ITG) In the Groove
 - (ITG) In the Groove 2
-- (Fraxtil) Tsunamix III 
-- (Fraxtil) Fraxtil's Beast Beats
-- (Fraxtil) Fraxtil's Arrow Arrangements
 
-Songs were downloaded from https://fra.xtil.net/simfiles/ and https://search.stepmaniaonline.net/packs/in+the+groove and are stored here for persistence.
+Songs were downloaded from  https://search.stepmaniaonline.net/packs/in+the+groove and are stored here for persistence.
+
+In The Groove/ITG typically refers to DDR beatmaps done with an eye towards pad play.
+
+Dataset info: https://paperswithcode.com/dataset/itg