Add `math` directive for switching typesetting library#246

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yhatt merged 7 commits intomainfrom

Jul 18, 2021

Commits on Jul 14, 2021

Add math global directive to choose preferred lib
yhatt
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Commits on Jul 16, 2021

Commits on Jul 17, 2021

Add test case of math global directive with unknown keyword
yhatt
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Commits on Jul 18, 2021