Add readme in themes folder, and remove uneccessary check in gruntfile

Gruntfile.js

@@ -233,11 +233,8 @@ module.exports = function (grunt) {
   grunt.registerTask('docker-build', ['run:docker-build']);
   
   grunt.registerTask('check', function() {
-      if (grunt.option('theme') == 'undefined') {
-        grunt.log.writeln('1- Valid argmuents are just "grunt" (will use default) or "grunt --theme=|default|black|matrix|squares|triangles"');
-    }
       if ((theme != 'default') && (theme != 'black') && (theme != 'matrix') && (theme != 'squares') && (theme != 'triangles')) {
-        grunt.warn('2- Valid argmuents are just "grunt" (will use default) or "grunt --theme=|default|black|matrix|squares|triangles"');
+        grunt.warn('Valid argmuents are just "grunt" (will use default) or "grunt --theme=|default|black|matrix|squares|triangles"');
     }
       if (grunt.option('theme') == 'default' || 'black' || 'matrix' || 'squares' || 'triangles') {
         grunt.log.ok();

package-lock.json

@@ -2950,7 +2950,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -3365,7 +3366,8 @@
         "safe-buffer": {
           "version": "5.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -3421,6 +3423,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -3464,12 +3467,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },

themes/README

@@ -0,0 +1,17 @@
+In order to build a specific Theme you need to run:
+
+grunt --theme=<themename>
+
+Available themes are: default, black, matrix, squares, triangles
+
+Ex. grunt --theme=black
+
+By default the original theme will be built.
+
+If you want to create a new theme:
+- Use the themes/default as source material
+- Make a copy in themes folder with a new name
+- Add your theme folder name on line 237,239 and 242
+- And then build as above, with your theme folder/name.
+
+That's it!