Added description about how to insert html into cheatsheet.
Added description about how to insert html into cheatsheet.

https://bugs.corefiling.com/show_bug.cgi?id=6922

paulcadman/reviki,paulcadman/reviki,paulcadman/reviki,CoreFiling/reviki,ashirley/reviki,ashirley/reviki,ashirley/reviki,CoreFiling/reviki,CoreFiling/reviki,CoreFiling/reviki,strr/reviki,strr/reviki,CoreFiling/reviki,ashirley/reviki,strr/reviki,ashirley/reviki,strr/reviki,strr/reviki,paulcadman/reviki