Maintenance: Add .editorconfig file to try to standardize formatting. (microsoft#194)

See: https://editorconfig.org

Closes: microsoft#181

Author: bgianfo

.editorconfig

@@ -0,0 +1,10 @@
+# Top-most EditorConfig file
+root = true
+
+# Use same style for all files
+[*]
+indent_style = space
+indent_size = 4
+end_of_line = crlf
+insert_final_newline = false
+trim_trailing_whitespace = true