Manipulation lab

[carriewright11]

This is a minor comment, but something that might help people focus on the new content in the lab: The backticks for 2020 are always a struggle and we tell them early on to change tricky names first.

Perhaps we should include a chunk of code that they run that shows them how to change all the name first or remind them about rename(). I think that is a really good practice.

I kind of recall a different dataset that has columns with numbers for multiple columns, but I don't remember which. although I think maybe we tried to do math with them later... idk. something to think about - could then use str_remove to get rid of any additional text - @avahoffman do you remember what that was?

[carriewright11]

student feedback - some thought questions about thinking through what is going on with the different joins would be helpful, as well as when/why we might need right/left joins for applications