[JS] Changelog Doesn't Follow Azure SDK's Changelog Policy 

need update the template from 
```
## 5.0.0 (2024-06-28)
    
**Features**

  - XXX

**Breaking Changes**
  - XXX
```
to
```
## 5.0.0 (2024-06-28)
    
### Features Added

  - XXX

### Breaking Changes
  - XXX
```

and make sure replace all the \*\*XXX\*\* to ### XXX from the old changelog