qr code popup on each site

[mikebarkmin]

On https://inf-schule.de/ there are qr code popups on each site, which are super helpful when you need to share a page to an audience. I would like to add something similar.

A user should be able to enable qr codes globally by setting the qr code option in the Hyperbook config to true.

Hyperbook config:

{
   ....
  qrcode: true
   ....
}

A user should be able to enable or disable qr codes per site by setting the qr code key in the front matter of a page to true:

Page

---
qrcode: true
---

The page setting always wins. So if you have qr code set to false in your Hyperbook config and set to true on a page. The qr code will show on this page.

To access the qr code, there should a qr code symbol right below the table of content symbol.

[mikebarkmin]

implemented in 79a36de