docs: improve writing style of TSC membership

[bandantonio]

Description

Make document more structurally and stylistically consistent

[thulieblack]

The new update one is part of the Onboarding Docs under the Maintainership

[bandantonio]

thanks for the work

this document is not so detailed as it should, some of the content is in this video I recorded some time ago for some new TSC members: https://www.youtube.com/watch?v=MfVUUbW2aos - maybe one day someone will find time to turn it into docs that are easy to update

Well, I can try to do it within this PR 😎