Fix for typo.
diff --git a/src/main/docgen/book.xml b/src/main/docgen/book.xml
index 9ed8698..7969c6e 100644
--- a/src/main/docgen/book.xml
+++ b/src/main/docgen/book.xml
@@ -1119,7 +1119,7 @@
<title>How do I contribute?</title>
<para>First you should <link linkend="mailing-lists">subsrcribe to the
- developer mailing list</link> to discuss what you plant to do.</para>
+ developer mailing list</link> to discuss what you plan to do.</para>
<para>Then, fork the project on Github, and start working on the
appropriate branch (see <link linkend="sourcecode">the repositories