Add "baggage" section to tracing docs

Closes gh-34977

spring-boot-project/spring-boot-docs/src/main/java/org/springframework/boot/docs/actuator/micrometertracing/baggage/CreatingBaggage.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.actuator.micrometertracing.baggage;
+
+import io.micrometer.tracing.BaggageInScope;
+import io.micrometer.tracing.Tracer;
+
+import org.springframework.stereotype.Component;
+
+@Component
+class CreatingBaggage {
+
+	private final Tracer tracer;
+
+	CreatingBaggage(Tracer tracer) {
+		this.tracer = tracer;
+	}
+
+	void doSomething() {
+		try (BaggageInScope scope = this.tracer.createBaggage("baggage1", "value1").makeCurrent()) {
+			// Business logic
+		}
+	}
+
+}