RFE: support hosting static websites

# Issue report

## What version of MicroCeph are you using ?

latest

## What are the steps to reproduce this issue ?

```
sudo microceph enable rgw

# prep user and .s3cfg

s3cmd ws-create s3://test-bucket --ws-index=index.html --ws-error=error.html
...
ERROR: S3 error: 405 (MethodNotAllowed)
```

## What happens (observed behaviour) ?

Getting an error

## What were you expecting to happen ?

Being able to set up static website hosting with MicroCeph RGW

## Additional comments.

We're missing support for this currently. We'd need to allow static websites in the rgw config `rgw_enable_static_website` and provide commands to set up urls, cf. https://www.ibm.com/docs/en/storage-ceph/7?topic=hosting-static-web-gateway-setup