Grab bag of small repo cleanup changes

[septract]

• Moved wrongly located example (per @scuellar)
• Remove old annotated tutorial versions
• Used the cn verify subcommand in scripts

[cp526]

@dc-mak has just done the cn verify part: https://github.com/rems-project/cn-tutorial/commit/86d90d8a124f0ce12c81801a3f08055e587f6b3c

[septract]

@cp526 I've rolled back the conflicting change. I think this is ready to merge.