Updating GDK Direction

Why is this change being made?

Now that GDK has an official home where it will get proper care and feeding, we need to set forth a direction to establish goals and communicate the progress as we make it publically.

This MR updates the GDK direction page to better meet the goals of the category direction template.

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

/cc @leipert