Fix documentation typos
What does this MR do?
It fixes 2 typos for documentation changes for backend and frontend tracking in the experiment guide.
Related to: !46688 (merged) and gitlab-org/growth/experimentation#20
Edited by Alex Buijs
It fixes 2 typos for documentation changes for backend and frontend tracking in the experiment guide.
Related to: !46688 (merged) and gitlab-org/growth/experimentation#20