Math support in Markdown on GitHub

[Aaron Meurer]

GitHub has finally added math support to markdown files, meaning LaTeX math between single or double dollar signs now renders on GitHub.

You can see an example of it in my pull request here https://github.com/sympy/sympy/pull/23488/files#diff-7ba870ff6b65326d74d081b9aa33ed75bd9a2a94ff3895a55ac02f5d0e96e77b. Click the "rich diff" file icon at the top right of the "custom-functions.md" file and scroll down to see some of the math in the document (reviews on that PR are welcome too :-).

For SymPy docs, you should still always look at the rendered preview, which you can see in the checks for a PR, but this feature is hopefully useful for quick checks. 

The LaTeX support also works in comments. For example here: https://github.com/sympy/sympy/pull/23488#issuecomment-1132045223

Unfortunately, it still doesn't support math on the wiki. I'm hoping they will add support for it.

Aaron Meurer