Update jQuery from 3.2.1 to 3.3.1 with SRI enabled

• CDN: https://www.jsdelivr.com/package/npm/jquery
• SRI: https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity

Signed-off-by: Takuya Noguchi takninnovationresearch@gmail.com

Closes #328 (closed)