minor update to code of conduct to fix missing link

Why is this change being made?

Suggesting linking to acceptable use policy to complete the [GitLab] reference in the context of using GitLab data for business purposes only. This link will conversely define what is acceptable use of sensitive data.

Does this MR meet the acceptance criteria?

Conformity

• Added description to this MR explaining the reasons for the proposed change, per say-why-not-just-what