Extend Privacy Policy with used Google scopes

public/static/docs/user-guide/privacy.md

@@ -42,6 +42,13 @@ section of this User Guide.
 
 ## Scopes
 
+userinfo.email scope (view your email address), userinfo.profile scope (see your
+personal info, including any personal info you've made publicly available), and
+openid scope (authenticate using OpenID Connect) are required to be used by
+Google Auth. DVC authorizes users via
+[Google's server](https://accounts.google.com/o/oauth2/auth) and doesn't access
+or collect users data used by Google Auth.
+
 DVC allows you to manage your Google Drive files and therefore the default
 scopes include read/write access to Google Drive.