chore: create .editorconfig

[ekoeryanto]

No description provided.

[erquhart]

Hmm maybe a bit too much for a general template, I'd expect folks to add this file if they want it.

[leptest]

I agree that most devs will drop config files like these. But it does help others contribute to this project.

[maxcell]

We opted for a tool like Prettier instead within the project. We are now able to format using a command like npm run format. I really appreciate this PR though and had a lot of conversation about how important it is for our projects to include this linting even if people remove it for the future.