Update README.md

README.md

@@ -50,6 +50,7 @@ Here is a complete snippet of it usage:
 new FingerAuthDialog(this)
         .setTitle("Sign in")
         .setCancelable(false)
+        .setMaxFailedCount(3) // Number of attemps
         .setPositiveButton("Use password", new DialogInterface.OnClickListener() {
             @Override
             public void onClick(DialogInterface dialogInterface, int i) {
@@ -84,6 +85,29 @@ if (hasFingerprintSupport)
     fingerAuthDialog.show();
 ```
 
+### Implementing your own method
+
+```java
+new FingerAuth(this)
+        .setMaxFailedCount(3) // Number of attemps
+        .setOnFingerAuthListener(new FingerAuth.OnFingerAuthListener() {
+            @Override
+            public void onSuccess() {
+                // do something
+            }
+
+            @Override
+            public void onFailure() {
+                // do something
+            }
+
+            @Override
+            public void onError() {
+                // do something
+            }
+        });
+```
+
 ---
 >See the *sample project* to clarify any queries you may have.