[Design] Add designs for customer support flow in Grant Hub

[michellema1208]

Four key objectives

• [ ] How will users contact support for help
• [ ] How will users be able to access knowledge base articles (i.e. specific articles, FAQ, etc.)
• [ ] How will users be able to submit feedback (either on current experience, submit any bugs, share product requests, etc.)
• [ ] How will we expose developer documentation (Github repo, Gitbook link)

Knowledge base articles: https://gitcoin.notion.site/Grant-Hub-Customer-Support-Playbook-a130d27011eb4a50b1131cfd905a3698

• Overall "learn about Grant Hub" article (can be for empty state as well as in a sticky section of the app like the footer)
• Knowledge base articles (3): how to create a project, edit a project, apply to a round
• Confirmation page after applying to a round -> share info on how to contact the round operator
• FAQ?