Edit the Tools and Tips Gmail Split Screen instruction

Why is this change being made?

Going through the documentation, I noticed that this particular set of instructions, while consistent with instructions elsewhere, were no longer valid. The settings it changes have been moved within GMail.

Does this MR meet the acceptance criteria?

Assign to DRI

• Did you assign this change to the correct DRI of the page or information you are changing?

Conformity

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