Add a NEWS entry.

ericsnowcurrently · ericsnowcurrently · commit 684a7dea1784 · 2021-09-15T09:30:27.000-06:00
diff --git a/Misc/NEWS.d/next/Build/2021-09-14-10-07-23.bpo-45020._VGGPv.rst b/Misc/NEWS.d/next/Build/2021-09-14-10-07-23.bpo-45020._VGGPv.rst
@@ -0,0 +1,4 @@
+Freeze stdlib modules that are imported during startup.  This provides
+significant performance improvements to startup.  If necessary, use the
+previously added "-X frozen_modules=off" commandline option to force
+importing the source modules.
