Add editorconfig file for automatically trimming whitespace

.editorconfig

@@ -0,0 +1,17 @@
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file.
+[*]
+insert_final_newline = true
+trim_trailing_whitespace = true
+charset = utf-8
+indent_style = tab
+indent_size = 4
+
+[*.{yml,yaml}]
+insert_final_newline = true
+trim_trailing_whitespace = true
+charset = utf-8
+indent_style = space
+indent_size = 2