Allow adding comments on any number of postSections

[evan-hossain]

Is your feature request related to a problem? Please describe.
Currently only postSection or renamed postSection can have comments enabled. I have for example, another post-like tab where I'd like to enable comments.

Describe the solution you'd like
Instead of single postSectionName, allow a list of post sections. The names can be changed using the menu options anyway.

Describe alternatives you've considered
One work around would adding more OR checks in the single.html file but that means essentially forking the repo.