(Very) basic foxbox discovery (includes setup app to foxbox)

[michielbdejong]

To get started with the "Discovering the Foxbox (includes setup app to foxbox)", I will try to implement the following super-basic and non-secure FTU flow:

• Connect the foxbox via ethernet
• Browse to http://foxlink.local/
• It shows you a page where you set the admin password
• When you submit the html form, it shows a page that suggests hyperlinks to a http-hosted admin app.

To do:

• Set hostname to 'foxlink.local' 'foxbox.local' during RPi image build process.
• Update https://github.com/fxbox/foxbox/blob/master/static/index.html adding the 'set admin password' form which does an xhr api call and then shows a http hyperlink to our basic web app.
• Add basic user manual to docs describing the setup flow.
• Add basic UI test that sets the admin password and checks that the hyperlink to the basic web app is shown on success.
• Manual testing on an actual RPi.

[michielbdejong]

Developing in https://github.com/michielbdejong/foxbox/tree/super-basic-ftu

[michielbdejong]

Depends on #16.

[michielbdejong]

Done in #20.