title: adding space after section numbers in TOC
body: <p>As can be seen from the sample below, my LaTeX book doesn't leave enough space between double-double-digit section numbers and the section titles in the automatically generated table of contents.  I seem to recall that there is a way to add extra space to all entries, but I can't find it online. </p>
  
  <p><a href="https://i.stack.imgur.com/s59M3.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/s59M3.png" alt="Sample table of contents entries"></a></p>
  
  <p>[Edit] In response to the comment below, here's an minimum working example:</p>
  
  <pre><code>\documentclass{book}
  \begin{document}
  \tableofcontents
  
  \chapter{Chapter}
  \chapter{Chapter}
  
  \setcounter{chapter}{10}
  \chapter{Chapter}
  \section{Section}
  \section{Section}
  
  \setcounter{section}{10}
  \section{Section}
  \section{Section}
  \subsection{Subsection}
  \subsection{Subsection}
  
  \setcounter{subsection}{10}
  \subsection{Subsection}
  \subsection{Subsection}
  
  \chapter{Chapter}
  
  \end{document}
  </code></pre>