Add in reference

[swzCuroverse]

I believe the original demo was borrowed from Peter's tutorial, and that tutorial's reference was not copied over.

See -

(https://doc.arvados.org/rnaseq-cwl-training/01-introduction/index.html)

"These lessons are based on Introduction to RNA-seq using high-performance computing (HPC) lessons developed by members of the teaching team at the Harvard Chan Bioinformatics Core (HBC). The original training, which includes additional lectures about the biology of RNA-seq, can be found at that link."

[swzCuroverse]

Also it uses images and text from the tutorial which is fine, but we might want to at least mention that it was re-used.

[swzCuroverse]

In the readme it states "Thanks to https://training.galaxyproject.org/training-material/topics/transcriptomics/tutorials/ref-based/tutorial.html for inspiration" but I am not sure where that came from except for perhaps other steps or data?