installation guide

[Stuart Ellis]

Thanks to all for the tips.

The wording of my original question was probably too vague.  I could
either put in FIXMEs (this is what I actually meant by placeholders) for
the designated screenshotter, or try to do the screenshots as I go.

It would definitely be best if one person does all of the screenshots,
especially since what I know about the Gimp at the moment probably
wouldn't fill the 500x375 rectangle, but I'm not sure if we have a
screenshotter to do the work.

I've seen custom FIXME tags cause odd-looking results in the output from
a Docbook, so it's useful to know that FIXMEs should be written with
<remark>.