Enhance TypeScript support section in use.mdx

Added information on extending the Directives interface for TypeScript support.

Author: thomasbuilds

src/routes/reference/jsx-attributes/use.mdx

@@ -33,7 +33,7 @@ const [name, setName] = createSignal("");
 
 ## TypeScript Support
 
-To type custom directives, extend the `DirectiveFunctions` interface:
+To type custom directives, extend the `DirectiveFunctions` interface
 
 ```ts
 declare module "solid-js" {
@@ -45,6 +45,18 @@ declare module "solid-js" {
 }
 ```
 
+If you just want to constrain the second argument to the directive function, you can extend the older `Directives` interface
+
+```tsx
+declare module "solid-js" {
+	namespace JSX {
+		interface Directives {
+			model: Signal<string>;
+		}
+	}
+}
+```
+
 ## Avoiding Tree-Shaking
 
 When importing a directive `d` from another module and using it only as `use:d`, TypeScript (via [babel-preset-typescript](https://babeljs.io/docs/babel-preset-typescript)) may remove the import, as it doesn’t recognize `use:d` as a reference to `d`.