Gruntfile: rm reference to defunct customizer

[skip sauce]

Gruntfile.js

@@ -190,10 +190,6 @@ module.exports = function (grunt) {
         src: '<%= concat.bootstrap.dest %>',
         dest: 'dist/js/<%= pkg.name %>.min.js'
       },
-      customize: {
-        src: configBridge.paths.customizerJs,
-        dest: 'docs/assets/js/customize.min.js'
-      },
       docsJs: {
         src: configBridge.paths.docsJs,
         dest: 'docs/assets/js/docs.min.js'