docs: Add sections on node now being a page

Updates #2297

docs/content/templates/functions.md

@@ -989,3 +989,17 @@ responses of APIs.
     {{ $resp.content | base64Decode | markdownify }}
 
 The response of the GitHub API contains the base64-encoded version of the [README.md](https://github.com/spf13/hugo/blob/master/README.md) in the Hugo repository. Now we can decode it and parse the Markdown. The final output will look similar to the rendered version on GitHub.
+
+
+## .Site.GetPage
+Every `Page` as a `Kind` attribute that shows what kind of page it is. While this attribute can be used to list pages of a certain `kind` using `where`, often it can be useful to fetch a single page by its path.
+
+GetPage looks up an index page of a given `Kind` and `path`. This method may support regular pages in the future, but currently it is a convenient way of getting the index pages such as the home page or a section from a template:
+
+```
+ {{ with .Site.GetPage "section" "blog" }}{{ .Title }}{{ end }}
+ ```
+ 
+This method wil return `nil` when no page could be found, so the above will not print anything if the blog section isn't found.
+
+The valid page kinds are: *home, section, taxonomy and taxonomyTerm.*