[PATCH v2 3/4] docs: Document SELinux issues

[Stephen Finucane]

On 30 Aug 00:35, Stephen Finucane wrote:
> Initial Docker setup caused me some heartache on Fedora. Briefly
> document the issues encountered to help other users.
> 
> Signed-off-by: Stephen Finucane <stephenfinucane at hotmail.com>

I extended this to included Daniel's reviewed-by, per comments on v1,
and merged this.

Stephen