bpo-35887: Add make regen-importlib step to importlib._bootstrap docstring (GH-11777)

Lib/importlib/_bootstrap.py

@@ -7,9 +7,9 @@ work. One should use importlib as the public-facing version of this module.
 
 """
 #
-# IMPORTANT: Whenever making changes to this module, be sure to run
-# a top-level make in order to get the frozen version of the module
-# updated. Not doing so will result in the Makefile to fail for
+# IMPORTANT: Whenever making changes to this module, be sure to run a top-level
+# `make regen-importlib` followed by `make` in order to get the frozen version
+# of the module updated. Not doing so will result in the Makefile to fail for
 # all others who don't have a ./python around to freeze the module
 # in the early stages of compilation.
 #