Update README.md

Added description for gpp_version

README.md

@@ -128,6 +128,7 @@ This script is stored and executed locally. The crawler also keeps a log of site
   - OptanonConsent_after_gpc: the isGpcEnabled string from One Trust’s OptanonConsent cookie after a GPC opt out signal was sent. The user is opted out if isGpcEnabled=1, and the user is not opted out if isGpcEnabled=0. If the cookie is present but does not have an isGpcEnabled string, we return “no_gpc”.
   - gpp_before_gpc: the value of the GPP string before a GPC opt out signal was sent
   - gpp_after_gpc: the value of the GPP string after a GPC opt out signal was sent
+  - gpp_version: the version of CMP API that obtains the GPP string (ie. v1.0 has a getGPPdata command while v1.1 remove the getGPPdata command and remove the return values in favor of callback functions)
   - urlClassification: the return value of [Firefox's urlClassificaton object](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/webRequest/onHeadersReceived#urlclassification), sorted by category and filtered for the following categories: `fingerprinting`, `tracking_ad`, `tracking_social`, `any_basic_tracking`, `any_social_tracking`.
   - OneTrustWPCCPAGoogleOptOut_before_gpc: the value of the OneTrustWPCCPAGoogleOptOut cookie before a GPC signal was sent. This cookie is described by OneTrust [here](https://my.onetrust.com/articles/en_US/Knowledge/UUID-2dc719a8-4be5-8d16-1dc8-c7b4147b88e0).
   - OneTrustWPCCPAGoogleOptOut_after_gpc: the value of the OneTrustWPCCPAGoogleOptOut cookie after a GPC signal was sent. This cookie is described by OneTrust [here](https://my.onetrust.com/articles/en_US/Knowledge/UUID-2dc719a8-4be5-8d16-1dc8-c7b4147b88e0).