Add ShaderMode mode.

Author: prisonerjohn

contrib_generate/sources.conf

@@ -1,4 +1,4 @@
-# Next ID: 259
+# Next ID: 260
 # Increment after assigning ID to new contribution
 
 [Library : 3D]
@@ -341,3 +341,4 @@
 169 \ https://py.processing.org/3/PythonMode.txt
 199 \ https://github.com/fathominfo/processing-p5js-mode/releases/download/latest/p5jsMode.txt
 220 \ https://github.com/processing-r/Processing.R/releases/latest/download/RLangMode.txt
+250 \ https://github.com/Izza11/shader-mode/releases/download/latest/ShaderMode.txt