Add an .editorconfig file, so we can have some consistency in the project. (I

don't care what settings we use, as long as we all use the same.)
 - Legacy-Id: 10551

.editorconfig

@@ -0,0 +1,15 @@
+# EditorConfig helps developers define and maintain consistent
+# coding styles between different editors and IDEs
+# editorconfig.org
+
+root = true
+
+# Settings for IETF datatracker
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = false
+insert_final_newline = true