Update doc/latex.rst

Author: jfbu

doc/latex.rst

@@ -196,13 +196,12 @@ Keys that you may want to override include:
       more complete TeX fonts and associated LaTeX packages.  The monospace
       font has been changed to better match the Times clone.
 
-   .. versionchanged:: 8.1.0 Configuration of math fonts should be done via
-      the ``'fontpkgmath'`` key, which is new at 8.1.0.  For ``'pdflatex'``
-      this key injects ``\usepackage{amssymb}`` which is thus now executed
-      after the contents of ``'fontpkg'``.
+   .. versionchanged:: 8.1.0 Custom configuration of math fonts, if any,
+      should be done via the ``'fontpkgmath'`` key, which is new at 8.1.0.
 
 ``'fontpkgmath'``
-   LaTeX package for math fonts.  It defaults to:
+   LaTeX configuration for math fonts, which is executed after contents of
+   ``'fontpkg'``.  It defaults to:
 
    - ``r'\usepackage{amssymb}'`` if :confval:`latex_engine` is set to
      ``'pdflatex'`` (or ``'uplatex'``).