[Tagging] swimming=* access tag

[Robert Skedgell]

I wonder whether it would be worth adding a swimming=* access tag to the
wiki and the list under "Water-based transportation" section of the page
for access=* (alongside boat=*/canoe=*)? This has been mentioned in the
discussion section, but not further discussed
<https://wiki.openstreetmap.org/wiki/Talk:Key:access#swimming.3D.2A>

It would be useful to note areas of open water where swimming is either
allowed or prohibited and this can be clearly determined fom signage at
the site etc. and recorded using values of yes, no, customers and
permissive.

-- 
Robert Skedgell (rskedgell)