chore: Update contributing docs

[alimpens]

Describe the pull request

What

Updates to CONTRIBUTING.md

Why

To make it clearer how users can open an issue and submit a PR

How

By following an existing CONTRIBUTING.md template.

Checklist

Before submitting your pull request, please ensure you have done the following. Check each checkmark if you have done so or if it wasn't necessary:

• Add or update unit tests
• Add or update documentation
• Add or update stories
• Add or update exports in index.* files
• Start the PR title with a Conventional Commit prefix, as explained here.

Additional notes

• Do we want to add a contributing section to Storybook as well?
• I've created a ticket to add SUPPORT.md
• Do we want to describe how we want to handle feature requests as well?

[VincentSmedinga]

Great effort, lots of essential knowledge in here. I have some suggestions on specific sentences.

I am a bit worried about the usability of the document. On GitHub, it looks like this – the various lengths of sections, lists and underlines make it appear a bit messy. Although I don’t see an easy way out. I’d be fine with the current state as a good start.