Fedora Design Team Docs: Revamp How to Join section

As part of &13 we are revamping https://docs.fedoraproject.org/en-US/design/ to include more information and make it look more inviting 😃 taking inspiration from our old Wiki page: https://fedoraproject.org/wiki/Design. We are going to break it down into sections and work on one part at a time.

Tickets for other sections can be found in the Fedora Team Resources epic: &13

For this ticket, we need to have what our How to Join as a New Contributor section will say. This just needs to be a text draft for now.

Some points and subheadings to include:

• Join the Element chat
• Taking ticket guidelines
• https://docs.fedoraproject.org/en-US/design/get-involved/