Add --local-partial-types note to dmypy docs (#15259)

Fixes #15214 but adding a note to
the dmypy docs.

Author: alanhdu

docs/source/mypy_daemon.rst

@@ -59,6 +59,11 @@ you have a large codebase.)
    back to the stable functionality.  See :ref:`follow-imports` for
    details on how these work.
 
+.. note::
+
+    The mypy daemon automatically enables ``--local-partial-types`` by default.
+
+
 Daemon client commands
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