[Size] tag not working, unless BBCode filter is sorted AFTER HTML filter

Issue Summary

The documentation mentions briefly that you may need to rearrange the filters to get it to work.

When HTML Filtering is enabled, it is specifically essential that BBCode be sorted AFTER the HTML filter. This is because the BBCode filter will change the BBCode into HTML, and the HTML filter will disallow and remove that code.

The clarification will help new users.

This took me a while to figure out, because I had sorted the BBCode filter first, thinking it would be useful to process BBCode first. Then I noticed that even in page source nothing was getting added.