Provide font metadata

[pathmapper]

Motivation:

• To prevent confusion when using the style with Maputnik. Currently there is a 404/warning logged because there is no metadata file available for
  https://orangemug.github.io/font-glyphs/glyphs/{fontstack}/{range}.pbf :
  

• To benefit from Maputnik's ability to show available fonts, e.g. this is how it looks with
  http://fonts.openmaptiles.org/{fontstack}/{range}.pbf, there is a metadata file available:
  
  This might be helpful in a case like Getting 404 error when trying to access glyphs url #30.

Some thoughts about possible options:

1. Add a metadata file to https://github.com/orangemug/font-glyphs.
2. Use https://github.com/orangemug/font-glyphs-v2 if Maputnik would be able to use such metadata.
3. Use https://maps.tilehosting.com/fonts/{fontstack}/{range}.pbf?key={key}. There is metadata available and we use Maptiler Cloud also as default for the tiles.

//cc @orangemug

[orangemug]

Since we use tilehosting.com for the data source, I think it makes sense to use it for the glyphs also. So I like option 3

[pathmapper]

Thanks for your feedback @orangemug !

Done in #37.

[orangemug]

@pathmapper I also added a glyphs.json to https://github.com/orangemug/font-glyphs just incase anybody wants to use it in future.

Note: I still think tilehosting.com is the correct solution here.

[pathmapper]

@orangemug great! If you change your mind we could revert the switch to tilehosting.com of course.

Your font-glyphs repositories are definately something I would like to cover for a host the tiles and assets yourself for complete liberty section here or better in context of maplibre/maputnik#337.