fix strict syntax mentioned in #1

• fix #1 (closed)

this MR also does the following:

• removes legacy DSL2.enabled command: it is now enabled by default
• comments out a local variable that is not being used: basecall_compute, which is not the params.basecall_compute we actually use/
• makes nextflow.config slightly more readable by grouping params. into a single params {} block, which removes the need of appending params. to each one of parameters.