QA: add editorconfig

Author: f3l1x

.editorconfig

@@ -0,0 +1,13 @@
+# EditorConfig is awesome: http://EditorConfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[{*.json, *.yml}]
+indent_style = space
+indent_size = 2