Improve internal doc of inflation module (#3288)

* improve internal doc

* Apply suggestions from code review

Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com>

* correct spelling

* Apply suggestions from code review

Co-Authored-By: joe petrowski <25483142+joepetrowski@users.noreply.github.com>

* improve not confusing expression

* improve general doc