add split_fastq

[maxulysse]

• new split_fastq params

Many thanks to contributing to nf-core/sarek!

Please fill in the appropriate checklist below (delete whatever is not relevant).
These are the most common things requested on pull requests (PRs).

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 necessary, also make a PR on the nf-core/sarek branch on the nf-core/test-datasets repo
• Ensure the test suite passes (nextflow run . -profile test,docker).
• Make sure your code lints (nf-core lint .).
• Documentation in docs is updated
• CHANGELOG.md is updated
• README.md is updated

Learn more about contributing: guidelines

[maxulysse]

Need docs

[apeltzer]

Sad that I didn't find anything to complain about :-(