copying and pasting code from wiki results in two onloads

[rmglennon]

https://github.com/mapzen/electron-quick-start/wiki/How-to-Electron-Workshop#lets-add-a-map

The template and this step results in there being town onloads, so the map does not display. Just needs a few text tweaks to give the context of where to paste the code without ending up with duplication.

https://github.com/mapzen/electron-quick-start/blob/master/index_renderer.js#L4

2. Add a global map variable just above the page loading handler function and a call to initMap() inside the loading handler.

const api_key = 'mapzen-xxxxxxx';
let map; // <--- global map variable

// handle window loading event
document.getElementById('body').onload = function () {
  console.log('good news: index window is loading!');  

  initMap(); // <--- initialize your map
};

[rmglennon]

PS - this was great! Thanks, @dianashk!