Fix failing markdown tests

Related to ef0b8c37bceb9018aa43dc8e05a8eeb8c929cb3b
Fix small styling issue for multiple choice quiz

The explanation should not have the js-answer class. Not sure how that
happened.
Add rudimentary course search to search bar

If you enter something like MATH 141 or MATH_141 or MATH141, it will
take you directly to that page. Otherwise, it will search the
descriptions, names, and numbers of all the courses in the database.