Update BCO RO nextflow documentation

[ChinweokeO]

• go through tutorial, and keep internal notes on things that need troubleshooting
• identify technical issues

https://biocompute-objects.github.io/bco-ro-crate/tutorial/

[ChinweokeO]

• [ ] Created pull requests to Stian https://github.com/biocompute-objects/bco-ro-crate/pull/3/commits