Fix indentation rules in .editorconfig (#916)

* Specify correct indentation level in .editorconfig

* Add exception to indent package.json with 2 spaces since NPM effectively mandates it

Author: cspotcode

.editorconfig

@@ -5,7 +5,10 @@ root = true
 [*]
 charset = utf-8
 indent_style = space
-indent_size = 2
+indent_size = 4
 end_of_line = lf
 insert_final_newline = true
 trim_trailing_whitespace = true
+
+[package.json]
+indent_size = 2