Add checkAddress sample

packages/phishing/README.md

@@ -1,5 +1,7 @@
 # @polkadot/phishing
 
+To check for sites that are on the list -
+
 ```js
 import { checkIfDenied } from '@polkadot/phishing';
 
@@ -7,3 +9,17 @@ const isOnDeny = await checkIfDenied(window.location.host);
 
 console.log(`isOnDeny=${isOnDeny}`);
 ```
+
+To check for addresses that are on the list -
+
+```js
+import { checkAddress } from '@polkadot/phishing';
+
+const info = await checkAddress('1b....');
+
+if (info) {
+  console.log(`The address is reported as ${info}`);
+} else {
+  console.log('Not reported');
+}
+```