Update Bomba description (#60)

Author: cdauth

assets/tuneDescriptions/bomba/en.md

@@ -1,5 +1,13 @@
 **Sign:** throw a grenade
 
+## Background
+
+**Name:** “Bomba” is the name of a commercial song from artist King Africa. The Call Break is inspired on the chorus of this song.
+
+**Musical background:** The main tune is inspired in song “Queremos Marcha” by Spanish artist Rosario ([YouTube](https://www.youtube.com/watch?v=aC6XTOwNBO8)) and the breaks inspired in song “Bomba” by King Africa ([YouTube](https://www.youtube.com/watch?v=QlPS16NeBO0)).
+
+**History:** Invented by a member of a former band in Valencia called Mandala around 2014
+
 ## Difficulty
 
 * **Low Surdo:** medium