Add attribute for handbook page to the tech stack

Tech Stack Update

Please do not merge this MR before the Business Systems Analysts have reviewed and approved.

Please take into account:

• If changing provisioners: You must also open an Update Tech Stack provisioner issue so all templates and Tech Stack information can be updated.
• If completing a system offboarding:
  • Follow the steps in the Tech Stack offboarding section

/cc @lisvinueza