docs: change "generateMetadata" to "generateViewport" in generateView…

…port docs

docs/02-app/02-api-reference/04-functions/generate-viewport.mdx

@@ -61,7 +61,7 @@ export function generateViewport({ params }) {
 
 > **Good to know**:
 >
-> - If the viewport doesn't depend on runtime information, it should be defined using the static [`viewport` object](#the-viewport-object) rather than `generateMetadata`.
+> - If the viewport doesn't depend on runtime information, it should be defined using the static [`viewport` object](#the-viewport-object) rather than `generateViewport`.
 
 ## Viewport Fields