Add Documentation for Adding the <param> Tag to Input Filter

Currently, there is no mention of the need to add the <param> tag to a site's input filter(s) on this project's page.

change:

Configure your HTML filter to accept <object>, <embed> and <script> tags by adding them to the list of accepted tags.

to:

Configure your HTML filter to accept <object>, <embed>, <script> and <param> tags by adding them to the list of accepted tags.