docs: add link for custom user property description and remove chunks

Author: aawnu

src/Analytics.php

@@ -130,21 +130,16 @@ public function post(): void
             ["consent" => $this->consent->toArray()],
         );
 
-        $chunkUserProperties = array_chunk($this->user_properties, 25, true);
-        $this->user_properties = [];
-
         $chunkEvents = array_chunk($this->events, 25);
         $this->events = [];
 
-        $chunkMax = count($chunkEvents) > count($chunkUserProperties) ? count($chunkEvents) : count($chunkUserProperties);
-
-        for ($chunk = 0; $chunk < $chunkMax; $chunk++) {
-            $body['user_properties'] = $chunkUserProperties[$chunk] ?? [];
+        foreach ($chunkEvents as $events) {
+            $body['user_properties'] = $this->user_properties;
             if (empty($body['user_properties'])) {
                 unset($body['user_properties']);
             }
 
-            $body['events'] = $chunkEvents[$chunk] ?? [];
+            $body['events'] = $events;
             if (empty($body['events'])) {
                 unset($body['events']);
             }

src/Facade/Type/AnalyticsType.php

@@ -43,10 +43,11 @@ public function setTimestampMicros(int|float $microOrUnix);
     public function setNonPersonalizedAds(bool $allow);
 
     /**
-     * The user properties for the measurement
+     * The user properties for the measurement (Up to 25 custom per project, see link)
      *
      * @var user_properties
      * @param AlexWestergaard\PhpGa4\Facade\Type\UserProperty $prop
+     * @link https://support.google.com/analytics/answer/14240153
      */
     public function addUserProperty(UserPropertyType ...$props);