Documentation update and added a full test

[RobJY]

I've made another pass or two through the documentation. It still needs work, but I'm starting a pull request so we can discuss.

This also adds a full test that can be run with:
nextflow run . -profile test_full,docker --outdir <OUTDIR>

PR checklist

• This comment contains a description of changes (with reason).
• If you've fixed a bug or added code that should be tested, add tests!
• If you've added a new tool - have you followed the pipeline conventions in the contribution docs
• If necessary, also make a PR on the nf-core/mcmicro branch on the nf-core/test-datasets repository.
• Make sure your code lints (nf-core lint).
• Ensure the test suite passes (nextflow run . -profile test,docker --outdir <OUTDIR>).
• Check for unexpected warnings in debug mode (nextflow run . -profile debug,test,docker --outdir <OUTDIR>).
• Usage Documentation in docs/usage.md is updated.
• Output Documentation in docs/output.md is updated.
• CHANGELOG.md is updated.
• README.md is updated (including new tool citations and authors/contributors).

[jmuhlich]

Thanks, I'm sure this feels like a lot of unrewarding busywork but the docs are crucial.

[nf-core-bot]

Warning

Newer version of the nf-core template is available.

Your pipeline is using an old version of the nf-core template: 3.0.2.
Please update your pipeline to the latest version.

For more documentation on how to update your pipeline, please see the nf-core documentation and Synchronisation documentation.