Added standard .editorconfig file

Author: helpfulrobot

.editorconfig

@@ -0,0 +1,17 @@
+# For more information about the properties used in this file,
+# please see the EditorConfig documentation:
+# http://editorconfig.org
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 4
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[{*.yml,package.json}]
+indent_size = 2
+
+# The indent size used in the package.json file cannot be changed:
+# https://github.com/npm/npm/pull/3180#issuecomment-16336516