feat(dev): don't proxy fonts

Use the local ones, this simplifies testing adding icons, for example.

webpack.config.js

  * target, undefined; otherwise, the path to the local file to be served.
  */
 function devServerProxyBypass({ path }) {
-    if (path.startsWith('/css/') || path.startsWith('/doc/')) {
+    if (path.startsWith('/css/') || path.startsWith('/doc/')
+            || path.startsWith('/fonts/')) {
         return path;
     }