Add system variables to the small TOC at top of BASIC appendix

appendix/basic_commands.tex

@@ -29,6 +29,9 @@ \chapter*{Commander X16 BASIC}
 	\item {\bfseries Functions}: describes the BASIC functions that return
 		values, such as calculations and string operations.
 
+	\item {\bfseries System Variables}: describes the special purpose variables
+		that are available in every BASIC program.
+
 \end{enumerate}
 
 \vspace{16pt}
@@ -2110,7 +2113,7 @@ \subsection{PRINT\#}
 be printed.  This can be any of the options available to the {\ttfamily PRINT}
 statement, including commas and semicolons used for formatting.  Not every
 device that can be written to with {\ttfamily PRINT\#} will be able to handle
-formatting, however.\\
+formatting.\\
 
 Example:\\