update docs to be correct
update docs to be correct

fixes: ADMIN-2880
flag=none

Test-Plan:
render docs (bundle exec rake doc:api) and make sure the docs are correct
for enrollment terms

Change-Id: Ia1c3ef400bf200f2b8d6fd35c7dd3cc8a3ac740a
Reviewed-on: https://gerrit.instructure.com/210242
Tested-by: Jenkins
Reviewed-by: Mysti Lilla <431d062aff1e8f25416b3a7b732fe6effdb03f9a@instructure.com>
QA-Review: Mysti Lilla <431d062aff1e8f25416b3a7b732fe6effdb03f9a@instructure.com>
Product-Review: Rex Fleischer <360d56e185853f069087eaa5288d1374fc56d750@instructure.com>

instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,djbender/canvas-lms