style(api): fix typo

Author: ukyo

Diff for: docs/api.md

@@ -1685,7 +1685,7 @@ driver.executeAsyncScript(
     'var callback = arguments[arguments.length - 1];' +
     'mailClient.getComposeWindowWidget().onload(callback);');
 driver.switchTo().frame('composeWidget');
-driver.findElement(By.id('to')).sendKEys('[email protected]');
+driver.findElement(By.id('to')).sendKeys('[email protected]');
 </pre></code>
 
 Example #3: Injecting a XMLHttpRequest and waiting for the result. In this