Bring docs up to date with some gui changes

docs/Manuals/Game/menu.rst

@@ -110,6 +110,10 @@ Load Another Tileset
   Available Tilesets Dialog
 
 
+Add Modpacks
+    Launches the modpack installer. This utility allows the Longturn community to create third-party content
+    and offer it for enhanced gameplay. For more information refer to :doc:`/Manuals/modpack-installer`.
+
 Tileset Debugger
     Opens the :guilabel:`Tileset Debugger` dialog. This option is documented in
     :doc:`/Modding/Tilesets/debugger`

docs/Manuals/Game/start-screen.rst

@@ -44,6 +44,7 @@ The following buttons are available on the :guilabel:`Start Screen`:
 * :guilabel:`Load Saved Game` -- Load a previously saved single player game. See `Load Saved Game`_ below.
 * :guilabel:`Start Scenario Game` -- Start a single player scenario game. See `Start Scenario Game`_ below.
 * :guilabel:`Options` -- Set client options. See `Options`_ below.
+* :guilabel:`Mods` -- Launch the modpack installer. See :doc:`/Manuals/modpack-installer`.
 * :guilabel:`Quit` -- Quit Freeciv21
 
 .. Note::

docs/Manuals/modpack-installer.rst

@@ -21,6 +21,10 @@ They can be installed using the modpack installer tool :file:`freeciv21-modpack-
 standard installation. There is also a command-line-only tool called :file:`freeciv21-modpack`, which is
 mainly useful for headless game servers.
 
+The easiest way to open the modpack installer is by clicking the :guilabel:`Mods` button on the
+:doc:`Start Screen </Manuals/Game/start-screen>` or the :guilabel:`Add Modpacks` option from the
+:guilabel:`Game` menu.
+
 In standard Freeciv21 builds, when you start the graphical modpack installer, it will show a list of modpacks
 curated by the Freeciv21 developers and Longturn community. You can select one and click
 :guilabel:`Install modpack`. The tool will download the files for the selected modpack, any other modpacks it