Documented where the build script expects the database directory to live.

git-svn-id: http://svn.igniterealtime.org/svn/repos/wildfire/trunk@4523 b35dd754-fafc-0310-a699-88a17e54d16e

documentation/docs/plugin-dev-guide.html

@@ -363,6 +363,7 @@ looks for plugin development directories in the following format:
  |- classes/        <- Resources your plugin needs (i.e., a properties file)
  |- lib/            <- Libraries your plugin needs
  |- src/
+     |- database    <- Optional database scripts for your plugin
      |- java        <- Java source code for your plugin
      |   |- com
      |       |- mycompany