Merge version into info

This PR merges `docker version` into `docker info`.

Closes #5856
I think this should either be:

> The 'docker version' command .. . Displaying 'docker info'

or

> The 'version' command .. . Displaying 'info'

Also the last bit (`Displaying ..`) should probably be replaced with: `Showing ..`.

Therefore rendering the output as:

> [DEPRECATED] The 'docker version' command has been deprecated. Showing 'docker info'