docs(eslint-plugin): [no-unnecessary-type-parameters] add admonition about rule's potential for subtlety (#9690)

put back an admonition for no-unnecessary-type-parameters

Author: kirkwaiblinger

packages/eslint-plugin/docs/rules/no-unnecessary-type-parameters.mdx

@@ -18,6 +18,11 @@ It can usually be replaced with explicit types such as `unknown`.
 At best unnecessary type parameters make code harder to read.
 At worst they can be used to disguise unsafe type assertions.
 
+:::warning
+This rule was recently added, and has a surprising amount of hidden complexity compared to most of our rules. If you encounter unexpected behavior with it, please check closely the [Limitations](#limitations) section below and our [issue tracker](https://github.com/typescript-eslint/typescript-eslint/issues?q=is%3Aissue+no-unnecessary-type-parameters).
+If you don't see your case covered, please [reach out to us](https://typescript-eslint.io/contributing/issues)!
+:::
+
 ## Examples
 
 <Tabs>