Draft: feat: add signpost support

[XerockXMG]

This change allows for users to configure their Signpost instance as a Navigation option.

Example

"navigation": [
    {
      "name": "Signpost",
      "url": "https://signpost.yourdomain.com/pokemon/{id}/google"
    },
    {
      "name": "Google Maps",
      "url": "https://maps.google.com/maps/place/{x},{y}"
    },
    {
      "name": "Apple Maps",
      "url": "https://maps.apple.com/maps?daddr={x},{y}"
    },
    {
      "name": "Waze",
      "url": "https://www.waze.com/ul?ll={x},{y}"
    },
    {
      "name": "Intel",
      "url": "https://intel.ingress.com/intel?pll={x},{y}"
    },
    {
      "name": "GeoURI",
      "url": "geo:{x},{y}?q={x},{y}"
    }
  ],

And if you remove all other navigation options it would force a user to use your Signpost instance.

NOTE: /google can be changed to apple or waze as well.

Signpost Repo: https://github.com/jfberry/signpost

[XerockXMG]

Had some leftover ? from testing. Removed those to bring things back to the way they were.

[XerockXMG]

I'm dumb. This won't work yet. Wasn't thinking about gym, pokestop, portal and route nav.

[jfberry]

I'm dumb. This won't work yet. Wasn't thinking about gym, pokestop, portal and route nav.

jfberry/signpost#6
gym, pokestop support added