In exercise 16, instructions and code editor warning tell user to do different things

[R-V-S]

The exercise advises the user to create this selector:
div.float-left { float: left; }

... which causes a warning in the code editor which says that the element is over-qualified, just use .float-left:

Not a big deal, but I imagine a user might be confused about why the workshop is telling them to do 2 different things.

Also in this exercise, 2 other warnings pop up about the repercussions of using padding & border along with width. It's a great warning, and it makes sense to introduce the user to this warning before introducing box-sizing... but maybe there could be a little parenthetical note in the exercise instructions telling the user to ignore the warning for now, and that it's just a warning (some users might not be familiar with the icon and might mistake it for an error symbol).

[getaaron]

@mikesjewett @stanidesis This is the second issue related to these warnings. Do you think they're helpful? Should we just turn them off?

[getaaron]

(Thanks, @R-V-S - agree about the second warning)