SVG markdown tags do not display in notebook

When you add inline svg in a markdown cell, such as this:

```html

```

It does not render in the notebook, but does render in print preview. See . Also, [this post](https://belloliva.wordpress.com/2017/10/27/embed-svg-into-jupyter-notebook/) even claims it is possible, but it does not seem to be. Same issue present in Jupyter Lab (even though the renderer is quite different).

This seemed like an excellent way to add simple figures to a notebook without creating extra files or ugly user-visible `SVG("...")` commands in input cells.

Reproduce the inline SVG example in a notebook markdown cell and compare its behavior with print preview and JupyterLab. Trace the notebook markdown rendering path; done means the SVG displays in the notebook without requiring an SVG command or an extra file.

Written by the indexing model from the issue text.