Update answer about code coverage (#3377)
Update answer about code coverage (#3377)

* Update answer about code coverage

Since linked issue was closed I took the [closing comment](https://github.com/cypress-io/cypress/issues/346#issuecomment-530967799) and made it the new answer (with minimal wording tweaks suitable in the context of this document).

I left the related resources in, since they still seems to be helpful and related to "coverage" in general. But I slightly modified the wording to
- no longer sound like code coverage is not there
- invite more links should anybody have one

* style: Use "full stack" instead of "full-stack"

* Update source/faq/questions/general-questions-faq.md

Co-authored-by: Jennifer Shehane <b76474446821c6f7360e4eee990dc1f8d635e16a@gmail.com>
cypress-io/cypress-documentation,cypress-io/cypress-documentation