* Draft the new maintainer guide

* Maintainer guide - Apply suggestions from code review

Co-Authored-By: Raihaan Shouhell <raihaanhimself@gmail.com>
Co-Authored-By: Tim Jacomb <t.jacomb@kainos.com>
Co-Authored-By: Daniel Beck <1831569+daniel-beck@users.noreply.github.com>

* Apply suggestions from code review

Co-Authored-By: Jeff Thompson <37345299+jeffret-b@users.noreply.github.com>
Co-Authored-By: Francisco Fernández <31063239+fcojfernandez@users.noreply.github.com>

* Maintainer guide - Replace the first role by "contributor"

* Maintainer guide - Add more details

* Maintainer guide - address some feedback

* Apply suggestions from code review by @daniel-beck

Co-Authored-By: Daniel Beck <1831569+daniel-beck@users.noreply.github.com>

* Update .github/PULL_REQUEST_TEMPLATE.md

Co-Authored-By: Daniel Beck <1831569+daniel-beck@users.noreply.github.com>

* Maintainer guide - more updates

* Maintainer Guide: Add info about the Security Release...