ref(metrics): add metric options for PHP (#15715)

Add metrics options for PHP

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Author: Litarnus

docs/platforms/php/common/configuration/options.mdx

@@ -241,6 +241,20 @@ This function is called with a log object, and can return a modified log event o
 
 </SdkOption>
 
+## Metrics Options
+
+<SdkOption name="enable_metrics" type='bool' defaultValue='true'>
+
+This option enables the metrics feature, which allows the SDK to send metrics. This is enabled by default.
+
+</SdkOption>
+
+<SdkOption name="before_send_metric" type='function (\Sentry\Metrics\Types\Metric $metric): ?\Sentry\Metrics\Types\Metric'>
+
+This function is called with a metric object, and can return a modified metric object, or `null` to skip the metric.
+
+</SdkOption>
+
 ## Transport Options
 
 Transports are used to send events to Sentry. Transports can be customized to some degree to better support highly specific deployments.