frontend UI implementation

[metalalive]

Discussed in #43

^{Originally posted by KalpasWang December 1, 2023}
@wingtkw @sandytang886
我比賽結束了，我想開始先實作出前端的 walking skeleton，我們要不要在前端用 TDD 開發呢？之前水球有說可以先用 cypress 做 e2e testing，再做出需要的功能。cypress 我雖然用過但是不熟，可以趁機學起來，不知道大家覺得如何？

[metalalive]

@KalpasWang ,

• the discussion in Frontend TDD - character selection and difficulty setup #43 should be converted into GitHub Issue, because what you've done is related to the game app dev,
• also, please remember to add github issue number in the messages of your subsequent commits . see previous discussion

[KalpasWang]

this issue will focus on ui part of frontend dev