Update the contributing guidelines

As I mentioned in the PR adding contributing guidelines #55 the contributing guidelines are incomplete. I would like to drop a PR finishing them, but I need this info:

1. Any way of official contact with 4C (preferably email)
2. Will the site be interactive in the future? Will it have settings/options/etc.? Plugins? (I’m just asking if you have it planned, not if you have it right now)
3. What label is for issues which need to be worked on?
4. Which build tool do you use for this site?
5. Which test framework?
6. Is there any way to skip ci for docs only? Something like a commit title with [ci skip]
7. Any styleguides you use for this repo.

Once I have this info I’ll be dropping a PR.

[FrancescoXX]

1. yes use [e-mail]
2. yes it will be more interactive for sure
3. what do you mean?
4. what do you mean? we use Next.js and Vercel to deploy
5. I have to check it
6. I have to check
7. I think you should contact xyz on the server

[SiddharthShyniben]

We cannot pre define labels for issues. It depends on the issue we are raising. So you can skip that point.

I meant the labels which should be worked on (like ready for dev or help wanted)