Disable diagnostic analyzers for entire folder/submodules

When you have submodules in your repository, it's not uncommon for those to be subject to a different quality bar than your main project. You may not even have a say in fixing issues upstream, or conventions may be totally different even.

In this case, you can introduce an .editorconfig in your repository which turns off all analyzer diagnostics for an entire directory path (and all subdirectories) by leveraging wildcards. Say your submodules are in a folder ext a couple levels up from your .editorconfig:

[../../ext/**/*.cs]
dotnet_analyzer_diagnostic.severity = none

Learned from this commit after following it from a related roslyn issue.