new readme update

README.md

@@ -1,2 +1,36 @@
-# use-simply-scroll-spy
+# use-simple-scroll-spy
+
 Tiny scroll spy react hook that just needs the element ids
+
+## Installation
+
+```
+pnpm i use-simply-scroll-spy
+```
+
+```
+yarn add use-simply-scroll-spy
+```
+
+```
+npm i use-simply-scroll-spy
+```
+
+## Usage
+
+```typescript
+const sectionIds = ["section-1", "section-2"];
+const MyComponent: React.FC = () => {
+  const activeIndex = useSimpleScrollSpy(sectionIds);
+  return (
+    <>
+      <div id="section-1">My content </div>
+      <div id="section-2">My content </div>
+    </>
+  );
+};
+```
+
+The code above is a very simply way of using this hook but the general idea is to track based on the URL hash. If you hit the page with `#section-2` as the default section, the `activeIndex` will be set propertly.
+
+My personal motivation for this project was the need in a very framework-agnostic in order to create an header with the active section