Maxime's suggestions for Hello Nextflow

[vdauwera]

From @maxulysse review on #486

• Why mixing multi lines comments (with the /.../ and single line comments //? Nowadays when I comment I use the shortcut from VS code and even multilines are using single comments, much less confusing I believe
• Why not using the tag directive for the processes when we use the flatten operator, so that we see a bit more than (1) (2) or (3)
• Why not using a params.yml over a params.json as json are really not meant to be edited by human hands

[vdauwera]

@maxulysse

• I included both single and multi line comments in the hello series just to illustrate how they're done. This is something people tend to have strong personal preferences for, so it seemed best to just show the syntax for both in passing and let them pick whichever they like. I don't expect much confusion, tbh, but if we get feedback about that we can certainly reevaluate.
• Because I didn't know about the tag directive at the time 😆. Could you show me an example of what that would look like / what we would gain? I do prefer to keep these examples as basic as possible to avoid overloading people with new information, so it's always going to be a pros/cons decision.
• Because coming from the WDL world JSON is my default go-to 😆. Happy to consider the .yml option instead, what would that look like?