Base 16 Geohash Support

[ThomasMAhern]

Would it be possible to add base 16 (0123456789abcdef) geohash support to the library (the default looks to be base 32). I think the old library supported specifying the base geohash.neighbors(' ', 16), but didn't think of it until now.

[ion-elgreco]

I can check but I'm quite swamped at the moment

[ThomasMAhern]

I'm running into things again where my workaround isn't ideal. I tried looking into trying it myself but I'm at a loss of what to do/which pieces connect.

[ion-elgreco]

@ThomasMAhern you just need to expose another expression that is the base
16 variant. And then on the python side, you can have param for the base