doc/server.org add info for save/load docker images

For deploying images to a server that does not have access to internet
or hub.docker.com
5 jobs for dev in 4 minutes and 35 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test Tools
passed #172429
test_tools

00:00:06

 
  Test Quality
passed #172430
web
code_quality

00:00:09

 
  Test Unit
passed #172431
web
test_browser_unit

00:00:08

passed #172432
web
test_server_unit

00:00:12

 
  Test Functional
passed #172433
docker x86_64
test_server_functional

00:03:59