InsertHTMLTextAction can be used to insert an arbitrary string of HTML
into an existing HTML document. At least two HTML.Tags need to be
supplied. The first Tag, parentTag, identifies the parent in
the document to add the elements to. The second tag, addTag,
identifies the first tag that should be added to the document as
seen in the HTML string. One important thing to remember, is that
the parser is going to generate all the appropriate tags, even if
they aren't in the HTML string passed in.
For example, lets say you wanted to create an action to insert
a table into the body. The parentTag would be HTML.Tag.BODY,
addTag would be HTML.Tag.TABLE, and the string could be something
like <table><tr><td></td></tr></table>.
There is also an option to supply an alternate parentTag and
addTag. These will be checked for if there is no parentTag at
offset.