[Tagging] Feature Proposal - RFC - footway=indoor

[Markus]

Hi Jeremiah,

Why not highway=footway + indoor=yes? This seems to be the most used
tagging for indoor ways. Current usage statistics are:

highway=footway + indoor=yes: 34, 326
highway=corridor: 13, 914
highway=footway + footway=indoor: 268
indoor=footway: 210

Also note that 31.33% of all tag combinations with indoor=yes are
highway=footway + indoor=yes.

Regards
Markus