Make new behavior overridable; update docs and examples

examples/center.js

@@ -1,6 +1,5 @@
 import Map from '../src/ol/Map.js';
 import View from '../src/ol/View.js';
-import {defaults as defaultControls} from '../src/ol/control.js';
 import GeoJSON from '../src/ol/format/GeoJSON.js';
 import {Tile as TileLayer, Vector as VectorLayer} from '../src/ol/layer.js';
 import {OSM, Vector as VectorSource} from '../src/ol/source.js';
@@ -45,11 +44,6 @@ const map = new Map({
     vectorLayer
   ],
   target: 'map',
-  controls: defaultControls({
-    attributionOptions: {
-      collapsible: false
-    }
-  }),
   view: view
 });