S3: error with non AWS S3 provider

Hello.

Some S3 providers require [`forcePathStyle`](https://github.com/aws/aws-sdk-js-v3/blob/main/clients/client-s3/src/endpoint/EndpointParameters.ts#L7), in case of self hosting a [garageHQ](https://garagehq.deuxfleurs.fr/) I got the following error:

```
2025-12-18T13:37:00.094Z error: Error [ERR_TLS_CERT_ALTNAME_INVALID]: Hostname/IP does not match certificate's altnames: Host: s3-codimd.s3.test.example.net. is not in the cert's altnames: DNS:*.test.example.net, DNS:test.example.net
```

At the same time, the [S3 client library](https://github.com/hackmdio/codimd/blob/develop/package.json#L33) is outdated, `0.1.0-preview.2` is 6 years old and does not support the `forcePathStyle` option. The latest `@aws-sdk/client-s3` is [`3.954.0`](https://github.com/aws/aws-sdk-js-v3/blob/main/clients/client-s3/CHANGELOG.md).

I think codimd should permit to configure all S3 parameters to adapt configuration for specific providers and use cases.

Regards.