Create new example contract / app: QuizChain

[zavodil]

Trustless quiz app with Rust contract and MeteorJS frontend

• new use case for a blockchain
• NEAR adoption since every player needs Near Account
• new app for fun and community incentivises

Contract: https://github.com/zavodil/quizchain/ UI: quizchain.org Documentation: Pending

Production: Pending (https://github.com/near/near-sdk-rs/issues/619)

[thisisjoshford]

Hey @zavodil ! Just checking in on the status of this issue.