docs: update readme

README.md

@@ -18,10 +18,25 @@ Import the `focusOn` function from the package and use it as an action on your m
 
 ```html
 <script>
-  import { focusOn } from 'svelte-focus-on';
+  import { useFocusOn } from 'svelte-focus-on';
+
+  const focusOn = useFocusOn();
 </script>
 
 <div class="modal" use:focusOn>
   <!-- ... -->
 </div>
 ```
+
+
+## Why
+
+I mostly made this package because I found myself using a similar action in different sites. You can most likely do your own action using similar packages.
+
+## Dependencies
+
+Most of the work of this packages is leveraged from:
+
+- *[dom-focus-lock](https://github.com/theKashey/dom-focus-lock)*: Focus trap.
+- *[aria-hidden](https://github.com/theKashey/aria-hidden)*: Hides everything from accessibility tools except the specified element.
+- *[body-scroll-lock](https://github.com/willmcpo/body-scroll-lock)*: Disables scrolling for the body.