Consider add a command line parameter `--bootstrap-config`

## Feature Request

### Describe your feature request related problem

We have some configuration items in `config file` will be lost effectiveness after bootstrap, such as:
```
"schedule": {
...
}

```
which let some users confuse about it.

### Describe alternatives you've considered

Consider using a separate config file to configure those parameters when bootstrapping the PD, and use `--bootstrap-config` to let the user make sense of it.