QR Codes For Homeserver Setup

**Is your feature request related to a problem? Please describe.**
In watching a new user setup their phone to use my homeserver having to manually type in the homeserver address adds time taken to setup / reduces ease of use.

**Describe the solution you'd like**
Ideally if there was the ability to scan a QR code to setup the app to use a custom homeserver it would speed up the setup / be easier to work with.