added note to man & cli docs on search limit

Signed-off-by: Nathan Hsieh <hsieh.nathan@gmail.com>

docs/man/docker-search.1.md

@@ -18,6 +18,8 @@ of images returned displays the name, description (truncated by default),
 number of stars awarded, whether the image is official, and whether it
 is automated.
 
+*Note* - Search queries will only return up to 25 results
+
 # OPTIONS
 **--automated**=*true*|*false*
    Only show automated builds. The default is *false*.

docs/sources/reference/commandline/cli.md

@@ -1868,6 +1868,8 @@ See [*Find Public Images on Docker Hub*](
 /userguide/dockerrepos/#searching-for-images) for
 more details on finding shared images from the command line.
 
+*Note* - Search queries will only return up to 25 results 
+
 ## start
 
     Usage: docker start [OPTIONS] CONTAINER [CONTAINER...]