Update various examples to use the Mapbox v4-API

examples/semi-transparent-layer.js

@@ -5,6 +5,7 @@ import {fromLonLat} from '../src/ol/proj.js';
 import OSM from '../src/ol/source/OSM.js';
 import TileJSON from '../src/ol/source/TileJSON.js';
 
+const key = 'pk.eyJ1IjoiYWhvY2V2YXIiLCJhIjoiY2pzbmg0Nmk5MGF5NzQzbzRnbDNoeHJrbiJ9.7_-_gL8ur7ZtEiNwRfCy7Q';
 
 const map = new Map({
   layers: [
@@ -14,7 +15,7 @@ const map = new Map({
     }),
     new TileLayer({
       source: new TileJSON({
-        url: 'https://api.tiles.mapbox.com/v3/mapbox.va-quake-aug.json?secure',
+        url: 'https://api.tiles.mapbox.com/v4/mapbox.va-quake-aug.json?secure&access_token=' + key,
         crossOrigin: 'anonymous',
         // this layer has transparency, so do not fade tiles:
         transition: 0