Better visibilty of helper text on Kaltura plugin page

fixes CNVS-10985

test plan:
1. go to /plugins/kaltura
2. make sure there are no copy errors on the page
3. the following text should show up at the bottom of the page as
bootstrapped <code> tags
(#{domain}/api_v3/index.php?service=stats&action=collect&...)

Change-Id: I7a155b53721da8989383cffd01413ba4836a815d
Reviewed-on: https://gerrit.instructure.com/29737
Reviewed-by: Jon Jensen <jon@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Steven Shepherd <sshepherd@instructure.com>
QA-Review: Steven Shepherd <sshepherd@instructure.com>