Add EditorConfig enforcing tabs

.editorconfig

@@ -0,0 +1,13 @@
+# See https://EditorConfig.org for documentation.
+
+# top-most EditorConfig file
+root = true
+
+# Indent with tabs by default.
+[*]
+indent_style = tab
+
+# Use spaces for YAML, Markdown.
+[*.md,*.mkd,*.yml,*.yaml]
+indent_style = space
+indent_size = 2