Datasets should not be in this repository

[Kerollmops]

We currently have our datasets files in this repository. It is not a good practice to put large non-code files in git repositories, it impacts clone and fetch times.

I propose that we move those files into a more practical file system like an S3 or anything else that will not be impacted by the number of revisions for this file. It will be easier for other teams than the core team to change the datasets without waiting for a PR to be merged on our side. Demos could use this storage, too, providing a centralized file system for all datasets provided by Meili.