docs: add note and banner about edge channel (#4640)

docs/components/atoms/StabilityEdge.vue

@@ -0,0 +1,20 @@
+<template>
+  <Alert icon="🧪">
+    {{ title }} is available on edge channel. Check out the <Link to="/guide/going-further/edge-channel">
+      Edge Channel Documentation
+    </Link> to beta test.
+  </Alert>
+</template>
+
+<script>
+import { defineComponent } from '@nuxtjs/composition-api'
+
+export default defineComponent({
+  props: {
+    title: {
+      type: String,
+      default: 'This feature'
+    }
+  }
+})
+</script>

docs/content/2.guide/3.directory-structure/10.pages.md

@@ -97,6 +97,8 @@ If you place anything within square brackets, it will be turned into a [dynamic
 
 If you want a parameter to be _optional_, you must enclose it in double square brackets - for example, `~/pages/[[slug]]/index.vue` or `~/pages/[[slug]].vue` will match both `/` and `/test`.
 
+::StabilityEdge{title="Optional dynamic params with [[slug]] syntax"}
+
 ### Example
 
 ```bash

docs/content/2.guide/6.going-further/8.edge-channel.md

@@ -0,0 +1,55 @@
+---
+title: Edge Channel
+---
+
+# Edge Release Channel
+
+Nuxt 3 is landing commits, improvements, and bug fixes every day. You can opt-in to test them earlier before the next release.
+
+After each commit is merged into the `main` branch of [nuxt/framework](https://github.com/nuxt/framework) and **passing all tests**, we trigger an automated npm release using Github Actions publishing Nuxt 3 packages.
+
+You can opt in to use this release channel and avoid waiting for the next release and helping Nuxt by beta testing changes.
+
+The build and publishing method and quality of edge releases are the same as stable ones. The only difference is that you should often check the GitHub repository for updates. There is a slight chance of regressions not being caught during the review process and by the automated tests. Therefore, we internally use this channel to double-check everything before each release.
+
+:::Alert
+Features only available on the edge channel are marked with an alert in the documentation.
+:::
+
+## Opting into the edge channel
+
+Update `nuxt` dependency inside `package.json`:
+
+```diff [package.json]
+{
+  "devDependencies": {
+--    "nuxt": "^3.0.0-rc.1"
+++    "nuxt": "npm:nuxt3@latest"
+  }
+}
+```
+
+Remove lockfile (`package-lock.json`, `yarn.lock`, or `pnpm-lock.yaml`) and reinstall dependencies.
+
+## Opting out from the edge channel
+
+Update `nuxt` dependency inside `package.json`:
+
+```diff [package.json]
+{
+  "devDependencies": {
+--    "nuxt": "npm:nuxt3@latest"
+++    "nuxt": "^3.0.0-rc.1"
+  }
+}
+```
+
+Remove lockfile (`package-lock.json`, `yarn.lock`, or `pnpm-lock.yaml`) and reinstall dependencies.
+
+## Using latest `nuxi` CLI from edge
+
+:::Alert
+All cli dependencies are bundled because of the building method for reducing `nuxi` package size. You can get dependency updates and CLI improvements using the edge channel.
+:::
+
+You can use `npx nuxi-edge@latest [command]` to try the latest version of the nuxi CLI.