Update README.adoc

Author: marcingrzejszczak

docs/src/main/asciidoc/README.adoc

@@ -61,6 +61,29 @@ Add Spring Cloud Sleuth to the classpath of a Spring Boot application (together
 			<artifactId>spring-cloud-sleuth-otel-autoconfigure</artifactId>
 		</dependency>
 	</dependencies>
+
+<!-- You 'll need those to add OTel support -->
+		<repositories>
+			<repository>
+				<id>spring-snapshots</id>
+				<url>https://repo.spring.io/snapshot</url>
+				<snapshots><enabled>true</enabled></snapshots>
+			</repository>
+			<repository>
+				<id>spring-milestones</id>
+				<url>https://repo.spring.io/milestone</url>
+			</repository>
+		</repositories>
+		<pluginRepositories>
+			<pluginRepository>
+				<id>spring-snapshots</id>
+				<url>https://repo.spring.io/snapshot</url>
+			</pluginRepository>
+			<pluginRepository>
+				<id>spring-milestones</id>
+				<url>https://repo.spring.io/milestone</url>
+			</pluginRepository>
+		</pluginRepositories>
 ----
 
 Consider the following HTTP handler: