Fix table in markdown and use dsfr table style

[nicolaskempf57]

Fix datagouv/data.gouv.fr#1345

To use DSFR table, we must allow <div> tag and class attribute in settings, like below. This will be added to udata settings.

MD_ALLOWED_TAGS = [
        'a',
        'abbr',
        'acronym',
        'b',
        'br',
        'blockquote',
        'code',
        'dd',
        'del',
        'div',
        'dl',
        'dt',
        'em',
        'h1',
        'h2',
        'h3',
        'h4',
        'h5',
        'h6',
        'hr',
        'i',
        'img',
        'li',
        'ol',
        'p',
        'pre',
        'small',
        'span',
        'strong',
        'ul',
        'sup',
        'sub',
        'table',
        'td',
        'th',
        'tr',
        'tbody',
        'thead',
        'tfooter',
        'details',
        'summary'
        # 'title',
    ]

    MD_ALLOWED_ATTRIBUTES = {
        'a': ['href', 'title', 'rel', 'data-tooltip'],
        'abbr': ['title'],
        'acronym': ['title'],
        'div': ['class'],
        'img': ['alt', 'src', 'title']
    }

[ThibaudDauce]

👍