Add a note about documentation of the Unix port (i.e., we don't, specifically).

This is mainly intended to make the documentation suitable for including in
distributions such as the Debian package, but won't be amiss on the web site
docs. It will look a bit out of place in the .HLP, but never mind.

[originally from svn r4690]

doc/blurb.but

@@ -12,12 +12,19 @@ page</a>.</p>}
 \cfg{text-filename}{puttydoc.txt}
 \cfg{winhelp-filename}{putty.hlp}
 
-\preamble PuTTY is a free (MIT-licensed) Win32 Telnet and SSH
+PuTTY is a free (MIT-licensed) Win32 Telnet and SSH client. This
-client. This manual documents PuTTY, and its companion utilities
+manual documents PuTTY, and its companion utilities PSCP, PSFTP,
-PSCP, PSFTP, Plink, Pageant and PuTTYgen.
+Plink, Pageant and PuTTYgen.
+
+\e{Note to Unix users:} this manual currently primarily documents the
+Windows versions of the PuTTY utilities. Some options are therefore
+mentioned that are absent from the Unix version; the Unix version has
+features not described here; and the \cw{pterm} and command-line
+\cw{puttygen} utilities are not described at all. The only
+Unix-specific documentation that currently exists is the man pages.
 
 \copyright This manual is copyright 2001-2004 Simon Tatham. All
 rights reserved. You may distribute this documentation under the MIT
 licence. See \k{licence} for the licence text in full.
 
-\versionid $Id: blurb.but,v 1.12 2004/10/24 15:41:44 jacob Exp $
+\versionid $Id: blurb.but,v 1.13 2004/10/24 22:57:36 jacob Exp $