doc: Restore some of the old installation instructions.

Follow-up to 227e0469db.

* doc/guix.texi (Binary Installation):
Revert wording for installing the Debian package.
Restore how to reproduce the binary tarball.
Restore how to uninstall.
(copying): Add copyright notice for Matthew Trzcinski.

Change-Id: Ib74199e39bd7a50ac58045f2bc47f61fc04eacb9

doc/guix.texi

@@ -125,6 +125,7 @@ Copyright @copyright{} 2023 Saku Laesvuori@*
 Copyright @copyright{} 2023 Graham James Addis@*
 Copyright @copyright{} 2023 Tomas Volf@*
 Copyright @copyright{} 2024 Herman Rimm@*
+Copyright @copyright{} 2024 Matthew Trzcinski@*
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -740,7 +741,7 @@ provide Guix through their own package managers.  The version of Guix
 may be older than @value{VERSION} but you can update it afterwards by
 running @samp{guix pull}.
 
-For Debian and Ubuntu-based systems, call:
+For Debian or a derivative such as Ubuntu, call:
 
 @example
 sudo apt install guix
@@ -803,6 +804,37 @@ When you're done installing Guix, @pxref{Application Setup} for extra
 configuration you might need, and @ref{Getting Started} for your first
 steps!
 
+@quotation Note
+The binary installation tarball can be (re)produced and verified simply
+by running the following command in the Guix source tree:
+
+@example
+make guix-binary.@var{system}.tar.xz
+@end example
+
+@noindent
+...@: which, in turn, runs:
+
+@example
+guix pack -s @var{system} --localstatedir \
+  --profile-name=current-guix guix
+@end example
+
+@xref{Invoking guix pack}, for more info on this handy tool.
+@end quotation
+
+@cindex uninstalling Guix
+@cindex uninstallation, of Guix
+Should you eventually want to uninstall Guix, run the same script with
+the @option{--uninstall} flag:
+
+@example
+./guix-install.sh --uninstall
+@end example
+
+With @option{--uninstall}, the script irreversibly deletes all the Guix
+files, configuration, and services.
+
 @node Setting Up the Daemon
 @section Setting Up the Daemon