Add region tags for GCP documentation that references the README.

README.md

@@ -12,6 +12,7 @@ Java idiomatic client for [Stackdriver Monitoring][product-docs].
 
 If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file
 ```xml
+<!-- [START monitoring_install_with_bom] -->
 <dependencyManagement>
   <dependencies>
     <dependency>
@@ -30,18 +31,21 @@ If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file
     <artifactId>google-cloud-monitoring</artifactId>
   </dependency>
 </dependencies>
+<!-- [END monitoring_install_with_bom] -->
 ```
 
 [//]: # ({x-version-update-start:google-cloud-monitoring:released})
 
 If you are using Maven without BOM, add this to your dependencies:
 
 ```xml
+<!-- [START monitoring_install_without_bom] -->
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-monitoring</artifactId>
   <version>1.99.2</version>
 </dependency>
+<!-- [END monitoring_install_without_bom] -->
 ```
 
 If you are using Gradle, add this to your dependencies