add .editorconfig

.editorconfig

@@ -0,0 +1,31 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+
+# starlark
+[*.star]
+indent_style = tab
+indent_size = 4
+tab_width = 4
+
+# go files (excluding templates)
+[*.{go,mod,sum}]
+indent_style = tab
+indent_size = 4
+tab_width = 4
+
+[*.nix]
+indent_style = space
+indent_size = 2
+
+[*.svg]
+insert_final_newline = false
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.{yaml,yml}]
+indent_style = space
+indent_size = 2