Differences to the `html4css1` Writer
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* Use only meta_ keywords recognized by HTML 5.
Add HTML5-compatible meta tags for docinfo items
"authors", "date", and "copyright".
Add a `viewport meta tag`__ to tell mobile browsers
to use the device-width as viewport.
__ https://developer.mozilla.org/en-US/docs/Web/HTML/Viewport_meta_tag
* Set table column widths with