add .editorconfig

Makes contributing and not messing up the codestyle easier

.editorconfig

@@ -0,0 +1,21 @@
+root = true
+
+
+[*]
+
+# change these settings to your own preference
+indent_style = space
+indent_size = 4
+
+# we recommend you to keep these unchanged
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false
+
+[{package,bower}.json]
+indent_style = space
+indent_size = 2