Add SG.5.01 to sec controls page

Why is this change being made?

Nik noticed that SG.5.01 was missing from the Security Controls handbook page and brought it to my attention. This MR is to update the Security Controls page to include SG.5.01.

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