Documenting solution proposals for `highway=path`

[supsup]

@aighes

Introducing *=shared_use will not change anything on the problem regarding difficulty.

I have to quote myself:

@supsup

I think two meaning of shared path are being confused:

1. Shared use as in he wikipedia article linked above, which is reglemened, usually signed, made so it is easy to bike on, usually is in urban settings (or possibly connecting setlements) etc. and in OSM it might be mapped as path or not, but definitely is not what most highway=paths are.
2. Shared use as in “access is no specifically designated by anything, so pretty much anything is legaly able to use it (as long as it is not a car)”. This is indeed the only thing that highway=paths have in common, making the tag very vague in its meaning.

I meant the first meaning. I do not just want to rename path, I would ideally abolish it and replace it with about 7 or more different primary tags (one of them being shared_use).