Add country or region to language data

[moyogo]

It would be useful to know what country or region a language or an orthography are used in.

One could query for the orthographies used in a country, or for the countries using an orthography.

[MrBrezina]

How about a separate database (I reckon someone like SILE might have one already) and cross-reference it from the CLI tool/website if need be?

[kontur]

Just for reference (no idea what their data is based on): https://github.com/googlefonts/gftools/tree/670d0a9d60b9bfaa6220fe87dbae66bf79a41fd7/Lib/gftools/lang/regions