Ref: https://webhint.io/docs/user-guide/hints/hint-apple-touch-icons/

* Adds a hook to insert body html.

* Adds a hook to insert head html.

* feat(welcome): new design

* squash: update strings

* squash: copy/paste error?

* squash: remove welcome page disabling checks

* squash: change strings again

* squash: background var

* squash: title and desc css as variables

Currently all.css is loaded after app.js. This means there may
not be a guarantee that the css is loaded before the js, which
is bad because the js does dom querying for sizes on elements,
but some element sizes will be affected by js. So instead load
css upfront and let the browser block as needed or at least
give the css a head start in racing javascript to load.