fix: reference office installation document

Signed-off-by: Elizabeth Danzberger <[email protected]>

admin_manual/configuration_files/file_conversion.rst

@@ -2,6 +2,6 @@
 File conversion
 ===============
 
-In the majority of cases, it is recommended that either the Pandoc or :ref:`Nextcloud Office <office-installation>` apps
+In the majority of cases, it is recommended that either the Pandoc or :doc:`Nextcloud Office <office/installation>` apps
 are enabled, as they provide the majority of file conversions available. Other apps may also
 support their own file conversions for other file types if more specific conversions are required.