how to add vim pandoc integration for markdown files

autocmd BufEnter *.md exe 'noremap <F5> :silent !start c:\tools\pd.bat  % <CR>'

and autorefresh plugin for chrome: so every time I hit F5 on markdown (.md) file I can see compiled html version in chrome

Where pd.bat file is following:

pandoc "%1" -f markdown -t html -s -o "%1.html"