fix(index.d.ts): optional parameters should have question mark

[benceHornyak]

Method definitions was missing ? from them indicating that they are optional parameter.

Please let me know if there is anything that I missed.

[eldadfux]

THANK YOU! All changes merged 🥳

Please reach out to me on our Discord server if you would like me to send you some cool Appwrite stickers and magnets! Please note that shipping might take longer times because of COVID19.

As a way of saying thank you, we have just invited you to join the Appwrite organization on GitHub. You can accept the invite by visiting https://github.com/orgs/appwrite/invitation. By joining our team, you will officially be an Appwrite maintainer on GitHub.

You can change your membership visibility settings, so your new Appwrite team membership badge will show up on your personal GitHub profile.

[eldadfux]

I'll release an updated tag and publish it on NPM as soon as possible!