Closes 21048: Index 'as' in import and with statements.

Doc/reference/compound_stmts.rst

@@ -348,7 +348,9 @@ may be found in section :ref:`raise`.
 The :keyword:`with` statement
 =============================
 
-.. index:: statement: with
+.. index::
+    statement: with
+    single: as; with statement
 
 The :keyword:`with` statement is used to wrap the execution of a block with
 methods defined by a context manager (see section :ref:`context-managers`).

Doc/reference/simple_stmts.rst

@@ -656,6 +656,8 @@ initializing the module, which includes execution of the module's code.
 If the requested module is retrieved successfully, it will be made
 available in the local namespace in one of three ways:
 
+.. index:: single: as; import statement
+
 * If the module name is followed by :keyword:`as`, then the name
   following :keyword:`as` is bound directly to the imported module.
 * If no other name is specified, and the module being imported is a top