Add .editorconfig to standardize line endings and such

[rjrjensen]

@UnstoppableMango, I'm going to add an editorconfig in there to help with formatting. Thanks for the callout on line endings!

And I agree with locking dependencies with the global.json file, especially when you have multiple projects in a solution, but since there's only two projects and I'll keep the version numbers incremented, I don't see much value here. Do you have more context about the use of the file?

Originally posted by @rjrjensen in #350 (comment)

[UnstoppableMango]

Do you have more context about the use of the file

It can do a number of things, but they're mostly MSBuild related and rarely come up. I primarily use the file for enforcing a minimum SDK version.

In the context of pairing sessions, I agree there is little value-add