chore: add balance sheet workshop to main repo

[jdwilkin4]

We are using the existing balance sheet project found in the Responsive Web Design cert and adding that to the new frontend cert.
We are keeping the ids the same as the original ids from the RWD cert project.

NOTE
Please review the sheet for the lecture scripts. The lectures come before the workshops and some of the step descriptions will need to be updated.

For example, if a lecture script already introduces a concept, then the language in the step shouldn't say "Now you are going to learn about X". It doesn't make sense to continuously repeat introductions, if it was already introduced just before this.

You can update those steps to say "In the lecture videos, you learn how to work with X like this: [show example]" .
That makes sense.

At the end of the day, the flow of the curriculum needs to make sense to campers. So we need to make sure the flow between the lecture videos, workshops and labs all make sense. 👍