docs: initial updating docs cleanup/refactor

Author: rigor789

content/guide/updating-an-app.md

@@ -0,0 +1,52 @@
+Before starting an update, it's recommended to have a clean git branch. Having a clean branch allows inspecting all the changes done during the update one last time before committing them.
+
+## Update steps
+
+### Update NativeScript CLI
+
+Every update starts with updating the NativeScript CLI to the latest version.
+
+```cli
+npm install -g nativescript@latest
+```
+
+Once installed, verify the version with:
+
+```bash
+$ ns -v
+# should print the version:
+v8.x.x
+✔ Up to date.
+```
+
+### Update runtimes, core and webpack
+
+For a quick update of the essential dependencies, run:
+
+```cli
+ns update
+```
+
+The following packages will be updated to their `latest` versions:
+
+```bash
+@nativescript/core
+@nativescript/webpack
+@nativescript/types     # if installed
+@nativescript/ios       # if installed
+@nativescript/android   # if installed
+```
+
+::: info Note
+
+If you prefer to update dependencies manually, you can do that as well, for example by manually changing versions in `package.json` then installing dependencies.
+
+:::
+
+### Clean project
+
+To make sure all dependencies are updated correctly, it's recommended to clean the project with:
+
+```cli
+ns clean
+```

content/guide/updating/common-steps.md

@@ -0,0 +1,15 @@
+---
+title: Updating from 6.x to 7.x
+description: Example.
+---
+
+<!-- @include: ./common-steps.md -->
+
+## Breaking Changes
+
+### Example Breaking Change
+
+```diff
+- foo
++ bar
+```

content/guide/updating/from-60-to-70.md

@@ -0,0 +1,29 @@
+---
+title: Updating
+description: Updating an app to the latest version of NativeScript.
+contributors:
+  - rigor789
+---
+
+Updating a NativeScript app is usually a quick process if done regularly. The following guides aim to document the general update steps, highlighting breaking changes (if any) when updating between specific versions.
+
+## Update guides
+
+- [Updating to latest](/guide/updating/to-latest)
+- More soon...
+
+## Updating to a tagged version
+
+To try upcoming features that have not been release yet, you can install the `next` tag of the CLI (built from the latest commit in the [NativeScript CLI repository](https://github.com/NativeScript/nativescript-cli/commits/main)) via:
+
+```cli
+npm install -g nativescript@next
+```
+
+You can also pass a tag to the `ns update` command.
+
+For example, to try all the latest features that have not made it into a stable release yet, you can run:
+
+```cli
+ns update next
+```

content/guide/updating/index.md

@@ -0,0 +1,8 @@
+import type { NSSidebarItem } from '../../../.vitepress/theme/vitepress-theme'
+
+export default [
+  {
+    text: 'To Latest',
+    link: '/guide/updating/to-latest',
+  },
+] as NSSidebarItem[]

content/guide/updating/sidebar.ts

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+---
+title: Updating to latest
+description: Updating to the latest version of NativeScript.
+contributors:
+  - rigor789
+---
+
+<!-- @include: ./common-steps.md -->

content/guide/updating/to-latest.md

@@ -1,5 +1,7 @@
 import type { NSSidebarGroup } from '../.vitepress/theme/vitepress-theme'
 
+import updatingItems from './guide/updating/sidebar'
+
 export default [
   {
     text: 'The Basics',
@@ -75,7 +77,9 @@ export default [
       },
       {
         text: 'Updating',
-        link: '/guide/updating-an-app',
+        link: '/guide/updating/',
+        hideChildren: true,
+        items: updatingItems
       },
     ],
   },