Update UX Desginer onboarding page to include buddy template and process info
Update source/handbook/engineering/ux/uxdesigner-onboarding/index.html.md
- Adds information regarding the ux buddy template issue -> gitlab-org/gitlab-design!81 (merged)
- Includes information regarding buddy responsibilities and link to handbook guidelines
Closes organization#187 (closed)
Edited by Rayana Verissimo