docs: Mention force update sideline

README.md

@@ -132,6 +132,15 @@ Here is a list of supported commands:
 * `face` - (optional) face overrides the default sideline face
 * `name` - (optional) backend name to display
 
+## 📇 How to force render the sideline on the next command?
+
+You can force update sideline by adding a hook or advice with the function
+`sideline-render-this`.
+
+```elisp
+(add-hook 'ts-fold-on-fold-hook #'sideline-render-this)
+```
+
 ## 📂 Example projects
 
 - [sideline-blame](https://github.com/emacs-sideline/sideline-blame)