docs: correct pre-containers claims and stale version notes in the guides

The custom rendering guide claimed "Portable Text has no concept of
block nesting", written before containers existed and now contradicted
by the containers concept page one sidebar group away. The true claim
was always about lists: a list is a flat run of sibling text blocks
carrying `listItem` and `level`, with no wrapper node, and that stays
true with containers, which nest blocks through object fields. Restate
it as the list-specific fact with a pointer to the containers page.

The guides' prerequisite notes had also drifted from the released
majors: seven pages claimed `@portabletext/editor` v6.x (current: 7.x)
and two claimed `@portabletext/toolbar` v7.x (current: 8.x). Refresh
all of them; the `@portabletext/react` v6.x note on the rendering page
is still accurate and stays.

Author: christianhg

apps/docs/src/content/docs/editor/getting-started.mdx

@@ -21,7 +21,7 @@ If you already have Portable Text content and want to display it, see [Render Po
 :::
 
 :::note[Prerequisites]
-This guide covers `@portabletext/editor` **v6.x**, `@portabletext/toolbar` **v7.x**, and `@portabletext/keyboard-shortcuts` **v2.x**. Requires React 18+. Check the [editor changelog](https://github.com/portabletext/editor/releases) for breaking changes.
+This guide covers `@portabletext/editor` **v7.x**, `@portabletext/toolbar` **v8.x**, and `@portabletext/keyboard-shortcuts` **v2.x**. Requires React 18+. Check the [editor changelog](https://github.com/portabletext/editor/releases) for breaking changes.
 :::
 
 You'll need to:

apps/docs/src/content/docs/editor/guides/behavior-cheat-sheet.mdx

@@ -11,7 +11,7 @@ import {PackageManagers} from 'starlight-package-managers'
 Below are some common behavior examples. You can also find a list of core behaviors [on GitHub](https://github.com/portabletext/editor/tree/main/packages/editor/src/behaviors).
 
 :::note[Prerequisites]
-These recipes are written for `@portabletext/editor` **v6.x** ([changelog](https://github.com/portabletext/editor/releases)).
+These recipes are written for `@portabletext/editor` **v7.x** ([changelog](https://github.com/portabletext/editor/releases)).
 :::
 
 To add these to your editor, first import `defineBehavior` as well as the `BehaviorPlugin`.

apps/docs/src/content/docs/editor/guides/create-behavior.mdx

@@ -8,7 +8,7 @@ import {LinkCard} from '@astrojs/starlight/components'
 Behaviors add functionality to the Portable Text Editor (PTE) in a declarative way.
 
 :::note[Prerequisites]
-This guide covers `@portabletext/editor` **v6.x** ([changelog](https://github.com/portabletext/editor/releases)). Requires React 18+.
+This guide covers `@portabletext/editor` **v7.x** ([changelog](https://github.com/portabletext/editor/releases)). Requires React 18+.
 :::
 
 For a deep dive into behaviors and how they work, check out [Behaviors](/editor/concepts/behavior/).

apps/docs/src/content/docs/editor/guides/custom-blocks.mdx

@@ -10,7 +10,7 @@ import {LinkCard} from '@astrojs/starlight/components'
 The Portable Text Editor handles text blocks (paragraphs, headings, lists) by default. To add structured content like images, code blocks, or calls to action, you define custom block types in your schema and tell the editor how to render and insert them.
 
 :::note[Prerequisites]
-This guide covers `@portabletext/editor` **v6.x** and `@portabletext/toolbar` **v7.x** ([changelog](https://github.com/portabletext/editor/releases)). Requires React 18+. You should be familiar with the [getting started guide](/editor/getting-started/) and [custom rendering](/editor/guides/custom-rendering/).
+This guide covers `@portabletext/editor` **v7.x** and `@portabletext/toolbar` **v8.x** ([changelog](https://github.com/portabletext/editor/releases)). Requires React 18+. You should be familiar with the [getting started guide](/editor/getting-started/) and [custom rendering](/editor/guides/custom-rendering/).
 :::
 
 ## How custom blocks work

apps/docs/src/content/docs/editor/guides/custom-rendering.md

@@ -8,7 +8,7 @@ sidebar:
 The Portable Text Editor gives you control of how it renders each schema type element. You need to explicitly tell it what. These choices have no impact on the Portable Text output—they only affect how the editor itself renders content.
 
 :::note[Prerequisites]
-This guide covers `@portabletext/editor` **v6.x** ([changelog](https://github.com/portabletext/editor/releases)). Requires React 18+.
+This guide covers `@portabletext/editor` **v7.x** ([changelog](https://github.com/portabletext/editor/releases)). Requires React 18+.
 :::
 
 :::note[Two rendering systems]
@@ -30,7 +30,7 @@ All the different render functions passed to `PortableTextEditable` can be defin
 
 Most follow the same pattern of reading `props` and conditionally rendering elements based on schema data.
 
-Lists are a bit unique. Portable Text has no concept of block nesting, so the solution is to use pure CSS to style them. We suggest [including this example CSS](https://github.com/portabletext/editor/blob/main/examples/basic/src/editor.css) or similar to manage list rendering.
+Lists are a bit unique. A list in Portable Text is flat: a run of sibling text blocks carrying `listItem` and `level`, with no wrapper node. ([Containers](/editor/concepts/containers/) nest blocks through object fields, but lists stay flat.) Visual nesting comes from CSS. We suggest [including this example CSS](https://github.com/portabletext/editor/blob/main/examples/basic/src/editor.css) or similar to manage list rendering.
 
 Here are basic implementations of some core types:
 

apps/docs/src/content/docs/editor/guides/customize-toolbar.mdx

@@ -8,7 +8,7 @@ import {PackageManagers} from 'starlight-package-managers'
 The [getting started guide](/editor/getting-started/) introduces the basics of setting up toolbar components. This guide provides some extra context, best practices, and patterns to get you started.
 
 :::note[Prerequisites]
-This guide covers `@portabletext/toolbar` **v7.x** and `@portabletext/keyboard-shortcuts` **v2.x** ([changelog](https://github.com/portabletext/editor/releases)). Requires `@portabletext/editor` v6.x and React 18+.
+This guide covers `@portabletext/toolbar` **v8.x** and `@portabletext/keyboard-shortcuts` **v2.x** ([changelog](https://github.com/portabletext/editor/releases)). Requires `@portabletext/editor` v7.x and React 18+.
 :::
 
 ## Render the toolbar inside the provider

apps/docs/src/content/docs/editor/guides/testing-behaviors.mdx

@@ -13,7 +13,7 @@ The Portable Text Editor ships with testing infrastructure you can use for your
 Both approaches use Vitest Browser Mode with Playwright, running tests against a real browser.
 
 :::note[Prerequisites]
-This guide covers `@portabletext/editor` **v6.x** and `racejar` **v2.x** ([changelog](https://github.com/portabletext/editor/releases)). Requires Vitest with Browser Mode and Playwright.
+This guide covers `@portabletext/editor` **v7.x** and `racejar` **v2.x** ([changelog](https://github.com/portabletext/editor/releases)). Requires Vitest with Browser Mode and Playwright.
 :::
 
 ## Setup