Add guidance on nuxt prerenderer

Author: matteason

content/1.get-started/15.using-govuk-vue-with-nuxt.md

@@ -52,6 +52,28 @@ export default defineNuxtConfig({
 })
 ```
 
+### Using static assets with Nuxt's prerenderer
+
+If you're using Nuxt's prerenderer to generate a static site with `nuxt generate`, the prerenderer will not pick up these assets, so
+you will need to copy them into the output directory afterwards. You can use the [copyfiles](https://github.com/calvinmetcalf/copyfiles#readme)
+package for this:
+
+```sh
+npm install copyfiles --save-dev
+```
+
+Add a script to your `package.json` which runs `copyfiles` after `nuxt generate` - for example:
+
+```json
+"generate": "nuxt generate && npx copyfiles -V -u 3 \".nuxt/dist/server/assets/**\" \".output/public\""
+```        
+
+You can then generate your static site with 
+
+```sh 
+npm run generate
+```
+
 ## Update your HTML template
 
 The main installation guide describes [changes you should make to your HTML template](/get-started/installing-govuk-vue#update-your-html-template).