[task] sidebar (component)

### ISSUE
- Group: `client`
-Type: `feature
-Detail: sidebar component and button

### TODO
1. [ ] 내 모임, 모각코, 지역설정, TIL 버튼
2. [ ] hover 기능 넣기

### Estimated time
>Pick one

### `1h`

Start in the client code by locating the sidebar component and its button entry point. Add buttons for 내 모임, 모각코, 지역설정, and TIL, then verify that the sidebar buttons have the requested hover behavior.

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