Restructure exampleSite once again, improve sections and flow

exampleSite/content.en/docs/content/organisation.md

@@ -0,0 +1,54 @@
+---
+title: Organisation
+weight: 10
+---
+
+# Content Organisation
+
+Hugo Book renders pages from a section as a sidebar menu. By default this is the `docs/` directory.
+
+## Example Directory Structure
+
+```
+content/
+├── docs/
+│   ├── _index.md
+│   ├── getting-started.md
+│   ├── guide/
+│   │   ├── _index.md
+│   │   ├── install.md
+│   │   └── configure.md
+│   └── reference/
+│       └── _index.md
+├── posts/
+│   ├── _index.md
+│   └── my-post.md
+└── _index.md
+```
+
+Pages are ordered by `weight` frontmatter, then alphabetically. Section `_index.md` files define the section entry in the menu.
+
+## Changing the Menu Section
+
+By default, pages under `docs/` are rendered as the sidebar menu. Change this with the `BookSection` parameter in [Configuration](/docs/getting-started/configuration/). Set to `'/'` to render all top-level sections.
+
+## Page Layouts
+
+The theme provides several layouts:
+
+| Layout    | Usage                | Description |
+| --- | --- | --- |
+| (default) | Documentation pages  | Sidebar menu + content + optional ToC |
+| `landing` | `layout: landing`    | Full-width, no sidebar. Used for homepages. |
+| `book`    | `layout: book`       | Single-page view with all subsections listed |
+| `posts`   | Pages under `posts/` | Blog-style with date, tags, pagination |
+
+Set the layout in frontmatter
+
+```yaml {filename=_index.md}
+---
+layout: landing
+---
+```
+
+See [Pages](/docs/content/pages/) for frontmatter reference and [Menus](/docs/content/menus/) for navigation controls.