Add an .editorconfig (#319)

Add an .editorconfig

.editorconfig

@@ -0,0 +1,18 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.go]
+indent_style = tab
+tab_width = 2
+
+[*.{json,yaml,yml}]
+indent_style = space
+indent_size = 2