Revert "Add --harmony option to live JSX compiler page"

This reverts commit 661bafb059687e5efcccf99819a920885ecaca0b.

(Depends on a newer version of JSXTransformer than the site currently has.)
[Docs] Fix tutorial line highlights, revert ajax in cb

(cherry picked from commit 66d6e3f3919d338e7f773220a8f32f147a8190d4)