Add missing comma

Author: usrbinsam

plugin.rb

@@ -19,7 +19,7 @@
  58 => "e23_wd2_00",
  46 => "e24_python_game_dev_00",
  13 => "m112_intro_prog_py_00",
- 84 => "m12_python_beyond_basics_00"
+ 84 => "m12_python_beyond_basics_00",
  14 => "m13_html_css_00",
  15 => "m13_js_00",
  16 => "M14_vr_00",