- Fix the attach examples according to the new attach behavior
- Add the option of adding the user to docker's group and avoid the usage of "sudo" before each command
- Included the sudo alternative as an example_header
Merge branch 'fix_examples_use_docs' of git://github.com/rogaha/docker into test-2592
Fix typos, add links, streamline content of #2592
Fixes #2701. Adds security section.
Merge pull request #2721 from metalivedev/2701-addmedia

Add security section and embed private registry video.
Merge pull request #2755 from metalivedev/test-2592

Replace PR#2592