document customising page title with sidebar

docs/more-pages.md

@@ -72,6 +72,16 @@ You can specify `alias` to avoid unnecessary fallback.
 
 !> You can create a `README.md` file in a subdirectory to use it as the landing page for the route.
 
+## Set Page Titles from Sidebar Selection
+
+A page's `title` tag is generated from the _selected_ sidebar item name. For better SEO, you can customize the title by specifying a string after the filename.
+
+```markdown
+<!-- docs/_sidebar.md -->
+* [Home](/)
+* [Guide](guide.md "The greatest guide in the world")
+```
+
 ## Table of Contents
 
 Once you've created `_sidebar.md`, the sidebar content is automatically generated based on the headers in the markdown files.