Add minimum NF version to quick start section of main README

[drpatelh]

The website currently trims off the badges off the top of the main README when rendered there. Given that this is currently the only place that the NF version is present in the README it would be good to add it somewhere else where it is quite visible.

e.g. as done here here

Will need to put this under bump versions control with nf-core/tools when updating the version of NF in the pipeline.

[KevinMenden]

So if I understand that correctly, we just add the Nextflow version to the Quick Start section of the README.md in the template, and then modify bump-versions to take this into account, right?

[drpatelh]

Yup. Exactly 👍🏽

[drpatelh]

I have put something like this here so the NF version needs to be recognised there and bumped if required.

[KevinMenden]

Alright, let's do that then, thanks! 👍

[ewels]

Done in #1064