Json File Output Options Change

Encountered an error while running the `deepfenceio/deepfence_secret_scanner:2.0.0` docker image.

```
flag provided but not defined: -output-path
```

Noticed that 2 related json output options were remove from an earlier PR https://github.com/deepfence/SecretScanner/pull/97/files

- `json-filename` and
- `output-path`

However, those options are still being used / referenced in some docs. They probably should be updated so as not to cause confusions.

E.g. https://github.com/deepfence/SecretScanner/blob/97a7eb4ad58be365ed6d3d28b406422edb11042a/docs/docs/secretscanner/quickstart.md?plain=1#L39

Side note, slightly curious about the reason behind the sudden change removing json output support, I didn't find much explanation / change info from the PR itself.