fix: prevent animation memory leaks and improve documentation

- Add proper cleanup for VerticalStick animation on unmount
- Fix license badge URL to point to correct repository
- Enhance README with better examples and autofill description

Author: nguyenthanhan

README.MD renamed to README.md

@@ -4,7 +4,7 @@
 [![npm](https://img.shields.io/npm/dm/react-native-otp-entry.svg?&kill_cache=1)]()
 [![install size](https://packagephobia.com/badge?p=react-native-otp-entry)](https://packagephobia.com/result?p=react-native-otp-entry)
 [![cov](https://anday013.github.io/react-native-otp-entry/badges/coverage.svg?&kill_cache=1)](https://github.com/anday013/react-native-otp-entry/actions)
-[![License](https://img.shields.io/badge/license-MIT-blue.svg?&kill_cache=1)](https://github.com/your-username/react-native-otp-entry/blob/main/LICENSE)
+[![License](https://img.shields.io/badge/license-MIT-blue.svg?&kill_cache=1)](https://github.com/anday013/react-native-otp-entry/blob/main/LICENSE)
 
 `react-native-otp-entry` is a simple and highly customizable React Native component for entering OTP (One-Time Password) on iOS, Android, and Web. It provides an intuitive and user-friendly interface for inputting one-time passwords in your React Native applications.
 
@@ -16,7 +16,7 @@
 
 - Simple and easy-to-use OTP input component.
 - Highly customizable appearance and styling.
-- Supports autofill
+- Supports autofill and placeholder text.
 - Effortlessly integrates with **React Native**, **Expo**, and **React Native Web** platforms.
 - Fully typed with TypeScript.
 - Fully covered with unit tests.
@@ -53,7 +53,11 @@ yarn add react-native-otp-entry
 2. Render the `OtpInput` component in your screen/component:
 
    ```jsx
-   <OtpInput numberOfDigits={6} onTextChange={(text) => console.log(text)} />
+   <OtpInput 
+     numberOfDigits={6} 
+     onTextChange={(text) => console.log(text)} 
+     onFilled={(text) => console.log(`OTP completed: ${text}`)}
+   />
    ```
 
 3. Customize the styling as per your requirements:
@@ -149,7 +153,7 @@ The `react-native-otp-entry` component exposes these functions with `ref`:
 
 ## License
 
-This project is licensed under the [MIT License](https://github.com/your-username/react-native-otp-entry/blob/main/LICENSE).
+This project is licensed under the [MIT License](https://github.com/anday013/react-native-otp-entry/blob/main/LICENSE).
 
 ## Contributing
 

src/OtpInput/VerticalStick.tsx

@@ -11,10 +11,15 @@ interface VerticalStickProps {
 
 export const VerticalStick: React.FC<VerticalStickProps> = memo(
   ({ focusColor, style, focusStickBlinkingDuration = 350 }) => {
-    const opacityAnim = useRef(new Animated.Value(1)).current;
+    const opacityAnimRef = useRef<Animated.Value | null>(null);
+    if (!opacityAnimRef.current) {
+      opacityAnimRef.current = new Animated.Value(1);
+    }
+    const opacityAnim = opacityAnimRef.current;
+    const animationRef = useRef<Animated.CompositeAnimation | null>(null);
 
     useEffect(() => {
-      Animated.loop(
+      animationRef.current = Animated.loop(
         Animated.sequence([
           Animated.timing(opacityAnim, {
             toValue: 0,
@@ -30,8 +35,16 @@ export const VerticalStick: React.FC<VerticalStickProps> = memo(
         {
           iterations: -1,
         }
-      ).start();
-    }, []);
+      );
+      
+      animationRef.current.start();
+
+      return () => {
+        if (animationRef.current) {
+          animationRef.current.stop();
+        }
+      };
+    }, [focusStickBlinkingDuration]);
 
     return (
       <Animated.View style={{ opacity: opacityAnim }}>