docs(eslint-plugin): [prefer-readonly-parameter-types] mention limitations (typescript-eslint#9260)

JoshuaKGoldberg · web-flow · commit 81fd60b9d871 · 2024-06-05T09:11:20.000-04:00
* docs(eslint-plugin): [prefer-readonly-parameter-types] mention limitations

* as readonly
diff --git a/packages/eslint-plugin/docs/rules/prefer-readonly-parameter-types.mdx b/packages/eslint-plugin/docs/rules/prefer-readonly-parameter-types.mdx
@@ -402,3 +402,8 @@ function foo(arg: MyType) {}
 ## When Not To Use It
 
 If your project does not attempt to enforce strong immutability guarantees of parameters, you can avoid this rule.
+
+This rule is very strict on what it considers mutable.
+Many types that describe themselves as readonly are considered mutable because they have mutable properties such as arrays or tuples.
+To work around these limitations, you might need to use the rule's options.
+In particular, the [`allow` option](#allow) can explicitly mark a type as readonly.
