docs(plugins): add note about composable usage

docs/content/2.guide/3.directory-structure/11.plugins.md

@@ -39,6 +39,26 @@ export default defineNuxtPlugin(nuxtApp => {
 })
 ```
 
+## Using Composables Within Plugins
+
+You can use [composables](/guide/directory-structure/composables) within Nuxt plugins:
+
+```ts
+export default defineNuxtPlugin((NuxtApp) => {
+  const foo = useFoo()
+})
+```
+
+However, keep in mind there are some limitations and differences:
+
+**If a composable depends on another plugin registered later, it might not work.**
+
+**Reason:** Plugins are called in order sequencially and before everything else. You might use a composable that dependants on another plugin which is not called yet.
+
+**If a composable depends on the Vue.js lifecycle, it won't work.**
+
+**Reason:** Normally, Vue.js composables are bound to the current component instance while plugins are only bound to `nuxtApp` instance.
+
 ## Automatically Providing Helpers
 
 If you would like to provide a helper on the `NuxtApp` instance, return it from the plugin under a `provide` key. For example: