Improve setup instructions

[ariostas]

I fixed the instructions for the setup with apptainer and I added a brief mention of what to do if using Docker Engine instead of Docker Desktop.

I still need to add instructions for setting up OpenSearch with apptainer.

[michmx]

Thanks a lot for the nice improvement!

[michmx]

@ariostas Did you set it as Draft only because of the OpenSearch part?

[ariostas]

Yeah, I haven't been able to get OpenSearch to work on Apptainer. Here are the steps I have so far:

mkdir /scratch/<username>/opensearch-apptainer; cd /scratch/<username>/opensearch-apptainer
mkdir -p ./opensearch/logs
apptainer pull --name opensearch.sif docker://opensearchproject/opensearch:latest
apptainer exec --bind ${PWD}/opensearch:/usr/share/opensearch/defaultconfig ./opensearch.sif cp -r /usr/share/opensearch/config /usr/share/opensearch/defaultconfig
apptainer instance start --bind ${PWD}/opensearch/logs:/usr/share/opensearch/logs --bind ${PWD}/opensearch/config:/usr/share/opensearch/config ./opensearch.sif opensearch
apptainer exec --env discovery.type=single-node --env OPENSEARCH_INITIAL_ADMIN_PASSWORD=<custom-admin-password> instance://opensearch /usr/share/opensearch/opensearch-docker-entrypoint.sh

However, there is a Java error in the last step that I haven't been able to get around.