Add Customizations/Hooks subsection

Author: igor-baiborodine

README.md

@@ -766,6 +766,19 @@ unsafe = true
 
 ## Customizations
 
+### Hooks
+
+If you need to integrate your website with a third-party service or to customize it further, you can use the following
+hook partials: hooks/head-end.html, hooks/body-start.html, and hooks/body-end.html. Copy the file in question into
+your site root's `layouts/partials/hooks` folder and add the necessary code, for example, as in this [hooks/body-end.html](https://github.com/igor-baiborodine/bilberry-hugo-theme-sandbox/blob/9c492fad08771295f529b9acdc17aa03865a52ad/layouts/partials/hooks/body-end.html)
+file hat contains integration with Umami web analytics.
+
+```html
+<script async defer src="https://analytics.umami.is/script.js"
+        data-website-id="29b02d61-3df1-433f-8bb7-cba0ec70c9f7"></script>
+```
+
+
 ### Favicons
 
 To add favicons, proceed with the following steps: