Add space for margin notes

Closes #18.

style/mu/base.dtx

@@ -1618,12 +1618,14 @@
 \if@twoside               
    \oddsidemargin 0.75in  
    \evensidemargin 0.4in  
-   \marginparwidth 0pt    
 \else                     
    \oddsidemargin 0.75in  
    \evensidemargin 0.75in
-   \marginparwidth 0pt
 \fi
+%    \end{macrocode}
+% \changes{v1.0.3}{2022/04/19}{Add space for margin notes. [VN]}
+%    \begin{macrocode}
+\marginparwidth 2.75cm
 \marginparsep 10pt        
 
 \topmargin 0.4in