Proposing to deprecate railway=razed and railway=dismantled

[Mateusz_Konieczny]

@ezekielf

Essentially, I wish we had better descriptive ways to tag a clearly visible old railbed to suggest “the imprint of an old railbed is currently visible in the terrain here” rather than “the railway that used to be here has been completely demolished”.

maybe add some extra tags? old_railway:sleepers=yes old_railway:rails=no old_railway:...