add ADOPTERS.md

[SteveL-MSFT]

PR Summary

Created ADOPTERS.md for adopters to submit PRs to add themselves to this list

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• Change is not breaking
• Make sure all .cs, .ps1 and .psm1 files have the correct copyright header
• Make sure you've added a new test if existing tests do not effectively test the code changed and/or updated documentation
• This PR is ready to merge and is not Work in Progress.
  • If the PR is work in progress, please add the prefix WIP: to the beginning of the title and remove the prefix when the PR is ready.

[bergmeister]

LGTM, is this for the Github dependency graph? I'll try and get proper links for the products using PSSA like e.g. PSEditorServices that is being used by the vs code extension, the VS extension, the jetbrains intellij extension, some vim extension, etc.

[SteveL-MSFT]

@bergmeister in general, we want the folks that adopt this feature to submit the PR. So PSEditorServices should be added to this list (@TylerLeonhardt or @rjmholt can do that), but there is a separate Adopters.md for PSEditorServices. CodeFactor uses PSSA, so I'll reach out to them to add themselves to this list once it's merged.

[JamesWTruher]

waiting on @bergmeister approval