Include h3-pg extension - Mailing list pgsql-pkg-debian

I couldn't find this when searching, so assume it's not available yet on
apt.postgresql.org.

H3-pg is an Uber Hexagon Extension commonly used with PostGIS and is growing
in popularity.

It relies on postgis and postgis_raster extensions.

https://github.com/zachasme/h3-pg

Would you consider carrying it?

Thanks,
Regina