Minor HeaderMatchesChecker Documentation Issue

[Gene Nagle]

I found a minor issue in the documentation. On the second code sample in the Example Configuration of http://www.scalastyle.org/rules-0.7.0.html#org_scalastyle_file_HeaderMatchesChecker, the copyright (c) parenthesizes need to be escaped for the regex "true" condition like:

<code>

<check enabled="true" class="org.scalastyle.file.HeaderMatchesChecker" level="warning">
 <parameters>
  <parameter name="regex">true</parameter>
  <parameter name="header">// Copyright \(C\) (?:\d{4}-)?\d{4} the original author or authors.</parameter>
 </parameters>
</check>

</code>

Thanks for the great tool!

Gene