Update Nix shell and add envrc

.editorconfig

@@ -1,15 +1,10 @@
-# EditorConfig helps developers define and maintain consistent
-# coding styles between different editors and IDEs
-# editorconfig.org
-
+# https://editorconfig.org
 root = true
 
 [*]
-charset = utf-8
-end_of_line = lf
-insert_final_newline = true
-trim_trailing_whitespace = true
 indent_style = space
-
-[*.{yml,yaml}]
 indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true