GFM does not respect inline CSS styling.

Summary

While GitLab Flavoured Markdown respects HTML, inline CSS styles applied are ignored.

Steps to reproduce

Add inline CSS to an HTML tag.

<!--- The line following this code block is written as follows: -->
<p style="text-align:center">This should be horizontally-centred.</p>

This should be horizontally-centred.

Expected behaviour

The line above should be centred horizontally in the div.

Actual behaviour

The inline CSS is ignored and the line is not centred.

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This behaviour may cause confusion and frustration between other Markdown-rendering tools and GitLab Issues, Milestones, Wikis, etc.