Adds a section on the self-assignment of issues on PD Page

Why is this change being made?

In a Kanban like agile system, issues are a pulled not pushed. Here, we're documented the motion that individuals should take when taking on issues from the Ready for Development stage.

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