doc: Explain that packages can be installed in the installation system.

* doc/guix.texi (Preparing for Installation): Add paragraph about
package installation in the installation system.

1 files changed, 5 insertions, 0 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 6d479763786..c8c755580a7 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -5982,6 +5982,11 @@ dependencies of your system configuration can be downloaded.  See the
 ``Networking'' section below.
 @end quotation
 
+The installation system includes many common tools needed for this task.
+But it is also a full-blown GuixSD system, which means that you can
+install additional packages, should you need it, using @command{guix
+package} (@pxref{Invoking guix package}).
+
 @subsubsection Keyboard Layout
 
 @cindex keyboard layout