fix: add IP property to user object (#160)

Author: tyiuhc

packages/experiment-browser/src/types/user.ts

@@ -76,6 +76,11 @@ export type ExperimentUser = {
    */
   library?: string;
 
+  /**
+   * Predefined field, can be manually provided
+   */
+  ip_address?: string;
+
   /**
    * The time first saw this user, stored in local storage, can be manually overridden
    */