v0.4.0

📦 Version v0.4.0 – 기능 추가

What's Changed

• Feature/today problem by @bienew22 in #36
• refactor: change today problem cnt and test data. by @heung115 in #37
• Feature/user rank by @bienew22 in #38
• Feature/user rank by @bienew22 in #39
• feat: update someting by @bienew22 in #40
• Feature/user badge by @bienew22 in #41
• Feature/cs-96 AI Gen DB by @in-up in #42
• Release/v0.4.0 by @heung115 in #43

Full Changelog: v0.3.1...v0.4.0