[PATCH] Provide basic manpage for plymouth

[Ray Strode]

Hi,

> As I have promised in a previous mail, I have written a manpage for
> plymouth to explain the basics of it and the usage of its primary
> configuration script, plymouth-set-default-plugin.

Thanks much for doing this.  I've pushed this out to master along with
a few follow up commits.

I'm really glad to get this in.  One area where plymouth has been weak
is documentation.

--Ray