Update help file for plugins
<p>The Archi Plug-ins Manager dialog will show. From here you can view installed plug-ins and their details.</p>
<h3>Installing</h3>
- <p>To install an Archi plug-in using this method you need to have the plug-in in Archi plug-in format. This is a zip file containing one or more *.jar files and a marker file. Examples of this type of Archi plug-in are the Collaboration and jArchi Scripting plug-ins. If the plug-in is a *.jar file you will need to install it manually (see below).</p>
+ <p>To install an Archi plug-in using this method you need to have the plug-in in Archi plug-in format. This is an archive file (*.archiplugin or *.zip file extension) containing one or more jar files and a marker file. Examples of this type of Archi plug-in are the Collaboration and jArchi Scripting plug-ins. If the plug-in is a jar file you will need to install it manually (see below).</p>
<p>To install a new plug-in, click the "Install New..." button. Select the plug-in file or files that you wish to install. You can select and install more than one plug-in if you wish. You will be prompted to restart Archi.</p>
