add example terraform config for an s3 bucket

[mikapfl]

Adding public access to an S3 bucket for a publicly available datalad repository via opentofu is quite a few lines of configuration because you essentially have to configure it twice.

I put this into the "Advanced example" category because it is only useful for people using terraform / opentofu.

[adswa]

hey @all-contributors please add @mikapfl for content

[allcontributors[bot]]

@adswa

I've put up a pull request to add @mikapfl! :tada: