Potential clarifying improvements to the widget docs

What does this MR do and why?

I wonder if these changes can help imrpove the clarity of the requirements around working with MR widgets and the MR widget extension framework PLUS the telemetry associated therein.

Related merge requests

• Related to Move widget extension telemetry docs to the exi... (!93334 - merged)
• Related to Document Merge Request Widget Extension Telemetry (!92819 - merged)