[ntp] add documentation
about how NTP clients and servers synchonize time with external servers
This was lost during merge of barclamp-ntp into crowbar-core
Not sure but I think that's not the right place for such documentation.
@bmwiedemann would it make sense to mention that to the doc team?
@fsundermeyer @taroth21 what do you think? Does it makes sense to include that in our doc instead?
Makes sense to add it to the documentation, see https://trello.com/c/NcP5wUge/
I'd still like to have a home for the ntp.dot source of the .svg, which will probably not be in the manual.
for what is not in git will be bitrotten