Cleaning thoughts

[carriewright11]

could split up the second lab into two sections cause we ended early but that might be just cause we didn't split into breakout rooms. If we do this it could be nice to add a question using filter and str_detect

Originally posted by @carriewright11 in #667

[carriewright11]

• remove the image about case_when - it uses the old way
• slide 71 is cut off
• separate and unite can use "." now without //?
• the beginning of making the Effect variable doesn't make sense - must not be printing everything on slide 60