Always Cohort Inline Discussions

Changes for the always cohort inline discussions open source PR. This is a new PR created after resolving conflicts in the old PR for DOC-1077 (https://github.com/edx/edx-documentation/pull/1)

I agree with @lamagnifica 's comments in the previous PR. I think this would be clearer if you said "If you want general topics to be divided, do some stuff" and "if you want inline topics to be divided, you don't need to do some stuff. To unify inline topics, do some stuff."

Also agree that "perform" causes issues with translation.