Please verify list of exercises

[bast]

@samumantha @eglerean can you please check that the list here for your session is correct?

https://coderefinery.github.io/2023-09-19-workshop/exercises/

[samumantha]

See PR #249

[bast]

I will adjust the page based on detailed schedule so don't worry about it now.

[samumantha]

• [x] mark exercises not planned to be done in workshop as "optional"