gEDA-user: [pcb] "first board" docs

[DJ Delorie]

> I'd prefer one board which is expanded by advanced stuff in later 
> chapters.

I don't plan on making "later chapters".  There is a whole User's
Guide which may be able to take advantage of such a plan, though.  In
the Getting Started doc I just want to give people the basics - get
them started.

> Add a lineout layer.

I keep hearing the term "lineout" but what is it?  I assume you mean
"outline" - the physical shape of the board.