Add custom option to SelectorManager

docs/modules/Selectors.md

@@ -112,9 +112,13 @@ If you need to manage your selectors programmatically you can use its [APIs][Sel
 
 The default UI can handle most of the common tasks but in case you need a more advanced logic/elements, that requires a replace of the default UI.
 
+All you have to do is to indicate the editor your intent to use a custom UI and then subscribe to the `block:custom` event that will give you all the information on any requested change.
 
 
 
+In the example below we'll replicate most of the default functionality by using only the Selector Manager API.
+
+
 
 ## Events
 

src/selector_manager/config/config.js

@@ -98,5 +98,8 @@ export default {
   // With this option enabled, also in the second case, the Component will be passed.
   // This method allows to avoid styling classes directly and make, for example, some
   // unintended changes below the visible canvas area (when components share same classes)
-  componentFirst: 0
+  componentFirst: 0,
+
+  // Avoid rendering the default Selector Manager UI.
+  custom: false
 };