User story
As someone looking at Growth features for design and development,
I want to access up-to-date figma resources,
So that I can work efficiently to learn about, re-use, and implement the designs.

Background
Multiple pages in the stable Growth experiments features figma spec file are out of date.

Acceptance Criteria

• Design updates to the following:
  • Update the Impact module on the Newcomer homepage page (whilst still preserving the previous impact module, similar to how this is presented in the Welcome survey)
  • Add specs related to the Positive reinforcement post-dialog messages and notifications in the Suggested edits page
  • Update the Mentor dashboard page (documentation, specs) - individually tracked in T349099
  • Add specs for the Send praise module on the Mentor dashboard page
  • Update specs to the Onboarding Dialog on the Suggested edits page, and link to the updated Onboarding Dialog pattern (see T329037)
  • Update specs related to changes on T332567 - individually tracked in T349821
• Product review for adding to relevant onwiki documentation