[Tagging] Proposal for standardization of sidewalk schema (+import)

[Ilya Zverev]

Frederik Ramm wrote:

> As written on the imports list, I think that separate mapping of
> sidewalks will not, and should not, be the norm;

In Russia it has been the norm for a long time. Not that we have mapped 
every sidewalk, but using the sidewalk=* tag is frowned upon.

IZ