Mauro Bieg mb21

## CommonMark-attributes-proposal.html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>CommonMark Spec</title>
<style type="text/css">
  body { font-family: Helvetica, arial, freesans, clean, sans-serif;
    line-height: 1.4;
    max-width: 48em;
    margin: auto;
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="UTF-8">
	<title>CommonMark Spec</title>
	<style type="text/css">
	body { font-family: Helvetica, arial, freesans, clean, sans-serif;
	line-height: 1.4;
	max-width: 48em;
	margin: auto;