Add docs for --dns-search=.
PR 6720 introduce that use `--dns-search=.` will not set `search` in `/etc/resolv.conf`.
@@ -1227,7 +1227,7 @@ removed before the image is removed.
-d, --detach=false Detached mode: run the container in the background and print the new container ID
--device=[] Add a host device to the container (e.g. --device=/dev/sdc:/dev/xvdc:rwm)
--dns=[] Set custom DNS servers
- --dns-search=[] Set custom DNS search domains
+ --dns-search=[] Set custom DNS search domains (Use --dns-search=. if you don't wish to set the search domain)
-e, --env=[] Set environment variables
--entrypoint="" Overwrite the default ENTRYPOINT of the image
--env-file=[] Read in a line delimited file of environment variables
