Introduce an editorconfig file

.editorconfig

@@ -0,0 +1,14 @@
+#-*-mode:conf-*-
+# editorconfig file (see EditorConfig.org)
+
+root                        = true
+
+[*]
+end_of_line                 = lf
+insert_final_newline        = true
+charset                     = utf-8
+trim_trailing_whitespace    = true
+indent_style                = space
+indent_size                 = 4
+tab_width                   = 4
+max_line_length             = 100