Add gren to release process

[mitchelsellers]

You can utilize the structure found in the Heif library to model this behavior.

[Bett-A-Fish]

this is gren:
https://github.com/github-tools/github-release-notes

where gren is used in heif: https://github.com/FileOnQ/Imaging.Heif/blob/61e0e6d0ec652e2217ecfe9fc08d2ec417602de6/.github/workflows/build_main.yml#L272

[mitchelsellers]

And the configuration file is here: https://github.com/FileOnQ/Imaging.Heif/blob/main/.grenrc.js

[SkyeHoefling]

@mitchelsellers do we want to spend time now setting up a github action for this? It'll give us better reusability across all the github projects that need standardized release notes?

[mitchelsellers]

That wouldn’t be horrible. I’ve adopted something in my own projects that wasn’t a reusable action but I could see the value in having one should any of the GitHub APIs change.

[SkyeHoefling]

Assigning this to @kenny-sellers. I would like us to create an open source GitHub action that automates release notes generation so we can use it across our various projects