update how to include the game files

Author: edwardchalstrey1

doc/developer.catalog.rst

@@ -32,7 +32,8 @@ Currently supported representations are:
 1. **Create the game file:**
 
    Use either :ref:`pygambit <pygambit>`, the Gambit :ref:`CLI <command-line>` or :ref:`GUI <section-gui>` to create and save game in a valid representation :ref:`format <file-formats>`.
-   Make sure the game includes a description, with any citations referencing the :ref:`bibliography <bibliography>` with the format ``[citation_key]_`` e.g. ``[Mye91]_``.
+   Make sure the game includes a description, with any citations referencing the :ref:`bibliography <bibliography>`.
+   Use a full link to the bibliography entry, so the link can be accessed from the file directly, as well as being rendered in the docs e.g. ```Rei2008 <https://gambitproject.readthedocs.io/en/latest/biblio.html#Rei2008>`_``
 
 2. **Add the game file:**