Update editorconfig with naming rules

[JamesNK]

• Private and internal fields start with _
• Const fields are pascal case

Copied from dotnet/runtime editorconfig.

[ghost]

Hey @dotnet/aspnet-build, looks like this PR is something you want to take a look at.

[danmoseley]

has anyone looked through all the csharp_ and dotnet_ entries in the runtime .editorconfig? there are lots we don't have. I wonder whether there are any that align with our practices.

what is the impact of a violation -- just warnings in VS?

[ghost]

Hi @danmoseley. It looks like you just commented on a closed PR. The team will most probably miss it. If you'd like to bring something important up to their attention, consider filing a new issue and add enough details to build context.

[JamesNK]

has anyone looked through all the csharp_ and dotnet_ entries in the runtime .editorconfig? there are lots we don't have. I wonder whether there are any that align with our practices.

what is the impact of a violation -- just warnings in VS?

Not even a warning. It's a suggestion, but it drives code generation and refactoring.

Most aspnetcore and runtime standards are the same. Notable differences are around var and private static fields (no s_ prefix in aspnetcore)