Add 'in v4.1.2' to fontsizev3 page

Author: dpvc

input/tex/extensions/fontsizev3.rst

@@ -4,12 +4,12 @@
 fontsizev3
 ##########
 
-The `fontsizev3` extension re-defines the various font-sizing commands
-(like ``\tiny``, ``\small``, ``\large``, etc.) to be the sizes that they
-were in MathJax v3 and in v4 prior to v4.1.2, when they were corrected
-to be consistent with the sizes used in actual LaTeX.  This extension
-is intended for those sites that have legacy content where the old
-sizing values are critical to the layout.
+The `fontsizev3` extension (nwe in v4.1.2) re-defines the various
+font-sizing commands (like ``\tiny``, ``\small``, ``\large``, etc.) to
+be the sizes that they were in MathJax v3 and in v4 prior to v4.1.2,
+when they were corrected to be consistent with the sizes used in
+actual LaTeX.  This extension is intended for those sites that have
+legacy content where the old sizing values are critical to the layout.
 
 This extension is **not** loaded automatically when the `autoload`
 extension is used.  To load the `fontsizev3` extension explicitly, add