Fix link reference being incorrect

This causes the build to fail

Author: Max Baldanza

reference/configuration/framework.rst

@@ -1721,7 +1721,7 @@ shared
 
 **type**: ``boolean`` **default**: ``true``
 
-If ``true``, it uses a `shared cache`_ so cached responses can be reused across
+If ``true``, it uses a `public cache`_ so cached responses can be reused across
 users. Set it to ``false`` to use a `private cache`_.
 
 .. versionadded:: 7.4