remove unused cm5 styles

Author: khanniie

client/styles/main.scss

@@ -6,9 +6,6 @@
 @import 'base/reset';
 @import 'base/base';
 
-// @import '../../node_modules/codemirror/lib/codemirror';
-// @import '../../node_modules/codemirror/addon/lint/lint';
-// @import '../../node_modules/codemirror-colorpicker/addon/codemirror-colorpicker';
 @import '../../node_modules/dropzone/dist/dropzone';
 @import '../../node_modules/primer-tooltips/build/build';