add course reset event to api docs

refs: CNVS-12590

This just adds the reset event types to the documentation
for the api endpoint.

Test Plan:  None, documentation change.

Change-Id: I119850466c58b61f785a74542de4bad02a743654
Reviewed-on: https://gerrit.instructure.com/35327
QA-Review: August Thornton <august@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Rob Orton <rob@instructure.com>
Product-Review: Nick Cloward <ncloward@instructure.com>