update docs

README.md

@@ -1,2 +1,21 @@
 # cookie
+
 Cookies, but with structs
+
+```go
+type User struct {
+	ID   uuid.UUID `cookie:"user_id"`
+	Name string    `cookie:"user_name"`
+}
+
+...
+
+var user User
+err := cookie.PopulateFromCookies(r, &user)
+if err != nil {
+    http.Error(w, err.Error(), http.StatusInternalServerError)
+    return
+}
+
+fmt.Println(user.ID, user.Name)
+```