Document local_partial_types config option (#9551)

Author: momohatt

docs/source/command_line.rst

@@ -453,6 +453,8 @@ potentially problematic or redundant in some way.
         This limitation will be removed in future releases of mypy.
 
 
+.. _miscellaneous-strictness-flags:
+
 Miscellaneous strictness flags
 ******************************
 

docs/source/config_file.rst

@@ -513,6 +513,9 @@ no analog available via the command line options.
 Miscellaneous strictness flags
 ******************************
 
+For more information, see the :ref:`Miscellaneous strictness flags <miscellaneous-strictness-flags>`
+section of the command line docs.
+
 .. confval:: allow_untyped_globals
 
     :type: boolean
@@ -529,6 +532,13 @@ Miscellaneous strictness flags
     Allows variables to be redefined with an arbitrary type, as long as the redefinition
     is in the same block and nesting level as the original definition.
 
+.. confval:: local_partial_types
+
+    :type: boolean
+    :default: False
+
+    Disallows inferring variable type for ``None`` from two assignments in different scopes.
+
 .. confval:: disable_error_code
 
     :type: comma-separated list of strings