Put example with - argument in <pre> tag for readability

h2/src/docsrc/html/build.html

@@ -88,8 +88,11 @@ You will get a list of targets. If you want to build the <code>jar</code> file,
 build jar
 </pre>
 <p>
-To run the build tool in shell mode, use the command line option <code>-</code> as in <code>./build.sh -</code>.
+To run the build tool in shell mode, use the command line option <code>-</code>:
 </p>
+<pre>
+./build.sh -
+</pre>
 
 <h3>Switching the Source Code</h3>
 <p>