feat: add metrics decrement

lib/nexus_semantic_logger/datadog_singleton.rb

@@ -21,6 +21,14 @@ module NexusSemanticLogger
       flush
     end
 
+    # Delegate to statsd (if available).
+    # @param [String] metric Metric name.
+    # @param [Array<String>] tags Additional tags.
+    def decrement(metric, tags: [])
+      statsd&.decrement(metric, tags: global_tags + tags)
+      flush
+    end
+
     # Delegate to statsd (if available).
     # @param [String] metric Metric name.
     # @param [Integer] ms Timing in milliseconds.