Add wellen Library to sources.

Author: prisonerjohn

contrib_generate/sources.conf

@@ -1,4 +1,4 @@
-# Next ID: 264
+# Next ID: 265
 # Increment after assigning ID to new contribution
 
 [Library : 3D]
@@ -225,6 +225,7 @@
 219 \ https://teddavis.org/xyscope/download/XYscope.txt
 254 \ http://www.kramann.info/ComposingForEveryone.txt
 260 \ https://github.com/sphaero/procmod/releases/latest/download/procmod.txt
+264 \ https://github.com/dennisppaul/wellen/releases/latest/download/wellen.txt
 
 [Library : Utilities]
 001 \ https://github.com/remixlab/proscene/releases/download/latest/proscene.txt