add apple touch icons

templates/2xx.html

@@ -8,6 +8,8 @@
 
 	<link rel='manifest' href='/manifest.json' >
 	<link id='theFavicon' rel='icon' type='image/png' href='/favicon.png' >
+  <link rel="apple-touch-icon" sizes="120x120" href="/apple-icon-120.png" >
+  <link rel="apple-touch-icon" sizes="180x180" href="/apple-icon-180.png" >
 
 	<style>
 /* auto-generated w/ build-sass.js */

templates/service-worker.js

@@ -5,6 +5,7 @@ const ASSETS = `cache${timestamp}`
 // `assets` is an array of everything in the `assets` directory
 const toCache = __shell__.concat(__assets__)
   .filter(filename => !filename.endsWith('.map'))
+  .filter(filename => !filename.startsWith('apple-icon'))
 const cached = new Set(toCache)
 
 // `routes` is an array of `{ pattern: RegExp }` objects that