Mention upgrade / uninstall docs are in admin guide

Fixes #124

Signed-off-by: jason yang <[email protected]>

index.rst

@@ -8,8 +8,8 @@ This guide aims to give an introduction to {Project}, brief
 installation instructions, and cover topics relevant to users building
 and running containers.
 
-For a detailed guide to installation and configuration, please see the
-separate `Admin Guide <{admindocs}>`_ for this version of {Project}.
+For a detailed guide to installation and configuration, as well as upgrading or
+uninstalling, please see the separate `Admin Guide <{admindocs}>`_ for this version of {Project}.
 
 ****************************************
 Getting Started & Background Information

quick_start.rst

@@ -36,6 +36,10 @@ and using {Project} on Mac and Windows machines
 are discussed in the `installation section of the admin guide
 <{admindocs}/installation.html>`__.
 
+If you have an existing version of {Project} installed from source, which
+you wish to upgrade or remove / uninstall, see the `installation section of the admin guide
+<{admindocs}/installation.html>`__.
+
 ***************************************
 Overview of the {Project} Interface
 ***************************************
@@ -138,6 +142,7 @@ Information about individual subcommands can also be viewed by using the
    Examples:
      $ {command} verify container.sif
 
+   For additional help or support, please visit https://www.apptainer.org/docs/
 
    For additional help or support, please visit https://www.apptainer.org/docs/