Added 8 to installation instructions

8. Add 'class="prodThumbImage"' to <li> tag in Snippets/ProductTinyImage.html.  Example:

> <li style = "height:%%GLOBAL_ProductTinyBoxHeight%%px; width:%%GLOBAL_ProductTinyBoxWidth%%px;" onclick="%%GLOBAL_TinyImageOverJavascript%%" id="TinyImageBox_%%GLOBAL_ProductThumbIndex%%" class="prodThumbImage">