Add EditorConfig file

Request Type: feature

How to reproduce: 

Component(s): 

Impact: 

Complexity: small

This issue is related to: 

**Detailed Description:**



**Other Comments:**

This file acts as a living style guide.  With an EditorConfig plugin installed, this file acts as a self-enforcing style guide.

See http://editorconfig.org for more details.

This should reduce problems such as the one in #8277.

Disclaimer: I'm one of the EditorConfig project team members.