JENKINS-26232 Make temporary directories configurable (added missing

help file)

src/main/resources/hudson/plugins/ec2/SlaveTemplate/help-tmpDir.html

@@ -0,0 +1,12 @@
<div>
  <p>
    This will override the location of the temporary directory used for storing and executing the init script.
    Leave empty to use the default value.<br />
    Note: Make sure the remote user has execute permissions to this directory.<br />
  </p>
  <p>
    If no value is provided the temporary directory will default to:<br />
    - UNIX: /tmp<br />
    - Windows: C:\\Windows\\Temp\\
  </p>
</div>