Don't teach jQuery APIs

[simonihmig]

While I think most guides content teaches native DOM APIs for good reasons, the component lifecycle guide still references jQuery APIs.

I believe this should be updated, as per RFC294 (even more so with RFC386, should this be accepted), to prevent "accidental" use of jQuery.

[jelhan]

Fixed by #200, isn't it?

[simonihmig]

@jelhan Yes, indeed! Thanks for mentioning!