Additional info for docker binary
Signed-off-by: Prasanna Gautam <prasannagautam@gmail.com>

I found that certain docker installations do not handle binding to the source directory quite right. Just writing it based on help from backjlack and tibor in IRC.
limiting to 80 chars

Signed-off-by: Prasanna Gautam < prasannagautam@gmail.com >
fixing punctuation and grammar

Signed-off-by: Prasanna Gautam <prasannagautam@gmail.com>
properly line wrapping

Signed-off-by: Prasanna Gautam <prasannagautam@gmail.com>
Merge pull request #9050 from prasincs/patch-1

Additional info for docker binary