added some docs about Settings API

packages/rocketchat-lib/README.md

@@ -4,6 +4,49 @@ This package contains the main libraries of Rocket.Chat.
 
 ### APIs
 
+#### Settings
+
+This is an example to create settings:
+```javascript
+RocketChat.settings.addGroup('Settings_Group', function() {
+    this.add('SettingInGroup', 'default_value', { type: 'boolean', public: true });
+
+    this.section('Group_Section', function() {
+        this.add('Setting_Inside_Section', 'default_value', {
+            type: 'boolean', 
+            public: true, 
+            enableQuery: { 
+                _id: 'SettingInGroup', 
+                value: true 
+            }
+        });
+    });
+});
+```
+
+`RocketChat.settings.add` type:
+
+* `string` - Stores a string value
+    * Additional options:
+        * `multiline`: boolean
+* `int` - Stores an integer value
+* `boolean` - Stores a boolean value
+* `select` - Creates an `<select>` element
+    * Additional options:
+        * `values`: Array of: { key: 'value', i18nLabel: 'Option_Label' }
+* `color` - Creates a color pick element
+* `action` - Executes a `Method.call` to `value`
+    * Additional options:
+        * `actionText`: Translatable value of the button
+* `asset` - Creates an upload field
+
+`RocketChat.settings.add` options:
+
+* `description` - Description of the setting
+* `public` - Boolean to set if the setting should be sent to client or not
+* `enableQuery` - Only enable this setting if the correspondent setting has the value specified
+* `alert` - Shows an alert message with the given text
+
 #### roomTypes
 
 You can create your own room type using (on the client):