Writes a series of tab strings that represent the indentation level for a line of markup characters.
The HtmlTextWriter.OutputTabs method uses the HtmlTextWriter.Indent property to determine how many tab strings to write to obtain the desired indentation.
The tab string is specified with the HtmlTextWriter.#ctor(System.IO.TextWriter, string) constructor. If no tab string is specified, the HtmlTextWriter.DefaultTabString constant (\t) is used.