Cygwin instructions:

- added missing period
- added markup so it's easier to tell which names are special

Doc/doc/doc.tex

@@ -1793,12 +1793,12 @@ This \UNIX\ is also followed by a space.
 
     Using the Cygwin installer, make sure your Cygwin installation
     includes Perl, Python, and the \TeX{} packages.  Perl and Python
-    are located under \menuselection{Interpreters} in the installer
+    are located under \menuselection{Interpreters} in the installer.
     The \TeX{} packages are located in the \menuselection{Text}
-    section; installing the tetex-beta, texmf, texmf-base, and
-    texmf-extra ensures that all the required packages are available.
-    (There may be a more minimal set, but I've not spent time trying
-    to minimize the installation.)
+    section; installing the \code{tetex-beta}, \code{texmf},
+    \code{texmf-base}, and \code{texmf-extra} ensures that all the
+    required packages are available.  (There may be a more minimal
+    set, but I've not spent time trying to minimize the installation.)
 
     The netpbm package is used by \LaTeX2HTML, and \emph{must} be
     installed before \LaTeX2HTML can be successfully installed, even