title: New generated GeneratedMSBuildEditorConfig file since recent upgrade
body: <p>I have been upgrading a project and since the latest version of Visual Studio 2019 was installed have found the following file being output to disk</p>
  <p><code>MyProjectName.GeneratedMSBuildEditorConfig.editorconfig</code></p>
  <p>I think that this is related to the roslyn compiler and was introduced in this commit: <a href="https://github.com/dotnet/roslyn/commit/de348c5a77977459a4138de0a62487e00980e28a#diff-e87b4990385fcfea8cf3f744bb8ad23e" rel="noreferrer">https://github.com/dotnet/roslyn/commit/de348c5a77977459a4138de0a62487e00980e28a#diff-e87b4990385fcfea8cf3f744bb8ad23e</a></p>
  <p>The obvious questions have arisen as to what this file is, what it does and whether it should be in source control or excluded. I know what .editorconfig files are for but this one was unexpected. My searching has turned up nothing. Can anyone shed any light on this?</p>