update based on latest template

Author: methane

peps/pep-0781.rst

@@ -37,6 +37,24 @@ and would help with writing type-hinted code for memory-constrained
 environments like WASM or micropython.
 
 
+Rationale
+=========
+
+Using Keyword
+-------------
+
+Avoiding the addition of a new :ref:`keyword <python:keywords>`
+(like :data:`__debug__`) would be attractive because more keywords means more
+complex language.
+
+However, adding a constant without a keyword (like :data:`__debug__`) requires
+special handling in both the compiler and runtime.
+
+By implementing ``__type_checking__`` the same way as ``False``, we avoid the
+need for the special handling.
+Therefore, making it a keyword is the simpler approach.
+
+
 Specification
 =============
 
@@ -49,23 +67,7 @@ Similar to :data:`typing.TYPE_CHECKING`, type checking tools should treat
 ``__type_checking__`` as ``True``.
 
 
-Rationale
-=========
-
-Difference from ``__debug__``
------------------------------
-
-:data:`__debug__` is not a keyword, but a built-in constant.
-Not adding a new keyword is attractive, but it requires special handling in
-both the compiler and the runtime to change the value of the constant
-depending on the startup option.
-
-By implementing ``__type_checking__`` the same way as ``False``,
-we avoid the need for special handling in both the compiler and runtime.
-Therefore, making it a keyword is the simpler approach.
-
-
-How to teach this
+How to Teach This
 =================
 
 Add this note to the ``typing.TYPE_CHECKING`` document: