docs: Fix typo in classes.dtx

base/classes.dtx

@@ -53,7 +53,7 @@
 %<*driver>
 \ProvidesFile{classes.drv}
 %</driver>
-              [2021/10/04 v1.4n
+              [2022/07/02 v1.4n
 %<article|report|book> Standard LaTeX document class]
 %<10pt|11pt|12pt>      Standard LaTeX file (size option)]
 %    \end{macrocode}
@@ -2538,7 +2538,7 @@
 %    The macro above uses |\@makechapterhead|\meta{text} to format the
 %    heading of the chapter.
 %
-%    We begin by leaving some white space. The we open a group in
+%    We begin by leaving some white space. Then we open a group in
 %    which we have a paragraph indent of 0pt, and in which we have the
 %    text set ragged right. We also reset the font.
 % \changes{v1.3c}{1995/05/25}{replace \cs{reset@font} with