Mark scribblehub announcement-card as an author-note

[nozwock]

In addition to the bottom author's note card, ScribbleHub also offers an announcement card (or news) option at the top.

This PR adds it to the Remove Author Note option.

Here's an instance of a chapter having it: https://www.scribblehub.com/read/426788-ecdysis/chapter/519798/

[dteviot]

@nozwock

Thanks for the commit.
However, it has the following minor issues.

1. The actual change can be:

 this.tagAuthorNotesBySelector(webPageDom, ".wi_authornotes, .wi_news");

2. You haven't added yourself to files readme.md or package.json, for credit.

Please fix, and squash, and I'll be delighted to accept.

also, if you want to change line 3 to

parserFactory.register("scribblehub.com", () => new ScribblehubParser());

feel free.

[dteviot]

@nozwock

And now that I look at it some more, this isn't used anymore.

    static nextTocPageUrl(baseUrl, nextTocIndex) {
        return `${baseUrl}?toc=${nextTocIndex}`;
    }

[nozwock]

@dteviot
Done, you may squash and merge now.

Let me know if there's anything else.

[dteviot]

@nozwock

Done. Thank you.