Updated readme

README.md

@@ -18,3 +18,12 @@ var code = SteamTotp.generateAuthCode('cnOgv/KdpLoP6Nbh0GMkXkPXALQ=');
 - `timeOffset` - If you know your clock's offset from the Steam servers, you can provide it here. This number of seconds will be added to the current time to produce the final time. Default 0.
 
 Returns your current 5-character alphanumeric TOTP code as a string.
+
+## getConfirmationKey(identitySecret, time, tag)
+- `identitySecret` - Your `identity_secret`, as a `Buffer`, hex string, or base64 string
+- `time` - The Unix time for which you are generating this secret. Generally should be the current time.
+- `tag` - The tag which identifies what this request (and therefore key) will be for. "conf" to load the confirmations page, "details" to load details about a trade, "allow" to confirm a trade, "cancel" to cancel it.
+
+**v1.1.0 or later is required to use this method**
+
+Returns a string containing your base64 confirmation key for use with the mobile confirmations web page.