Add editorconfig

.editorconfig

@@ -0,0 +1,16 @@
+; top-most EditorConfig file
+root = true
+
+[*]
+charset = utf-8
+end_of_line = LF
+indent_style = space
+indent_size = 4
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[Makefile]
+indent_style = tab
+
+[.github/**/*.yml]
+indent_size = 2