Integrate comments from old tutorial drafts

[septract]

See annotated tutorial documents here:

• https://github.com/rems-project/cn-tutorial/blob/1fc7c0a429def2decc251cb375a84dfbb79926cb/src/tutorial-with-bcp-comments.md - @bcpierce00
• https://github.com/rems-project/cn-tutorial/blob/1fc7c0a429def2decc251cb375a84dfbb79926cb/src/tutorial-with-cht-comments.adoc - @cassiatorczon
• https://github.com/rems-project/cn-tutorial/blob/1fc7c0a429def2decc251cb375a84dfbb79926cb/src/tutorial-with-ps-comments.adoc - @PeterSewell

Comments may or may not have been integrated into the main tutorial. The people who wrote the comments should probably check