Added todo list to README.
Added todo list to README.

dutchiexl/BehatHtmlFormatterPlugin,dutchiexl/BehatHtmlFormatterPlugin,cckakhandki/Behat-Html-Formatter,rn0/BehatHtmlFormatterPlugin,fonsecas72/BehatHtmlFormatterPlugin,arminkhoshbin/BehatHtmlFormatterPlugin,rn0/BehatHtmlFormatterPlugin,arminkhoshbin/BehatHtmlFormatterPlugin,pdaoust/BehatHtmlFormatterPlugin,cckakhandki/Behat-Html-Formatter,pdaoust/BehatHtmlFormatterPlugin,fonsecas72/BehatHtmlFormatterPlugin