Add docs to useToggle hook

Author: Olaf Sulich

docs/useToggle.md

@@ -0,0 +1,35 @@
+# `useToggle`
+
+Tracks value of a boolean
+
+## Usage
+
+```jsx
+import { useToggle } from 'use-haki';
+
+const App = () => {
+  const { on, toggle } = useToggle();
+
+  return (
+    <div>
+      <span>{on && 'Hi there 👋'}</span>
+      <button onClick={toggle}>toggle me 👀</button>
+    </div>
+  );
+};
+```
+
+## Reference
+
+```ts
+const { on, toggle } = useToggle(initialOn);
+```
+
+- **initialValue** - initialOn by default is false
+- **on** - toggle state
+- **toggle** - function that toggle `on` state
+
+### Returns
+
+- **toggle**
+- **on**