Fix broken links in observability section of reference documentation.

Add back micrometer-docs-generator plugin in version 1.0.1.

Fixes: #4236

spring-data-mongodb-distribution/pom.xml

@@ -22,6 +22,11 @@
 	<properties>
 		<project.root>${basedir}/..</project.root>
 		<dist.key>SDMONGO</dist.key>
+
+		<!-- Observability -->
+		<micrometer-docs-generator.inputPath>${maven.multiModuleProjectDirectory}/spring-data-mongodb/</micrometer-docs-generator.inputPath>
+		<micrometer-docs-generator.inclusionPattern>.*</micrometer-docs-generator.inclusionPattern>
+		<micrometer-docs-generator.outputPath>${maven.multiModuleProjectDirectory}/target/</micrometer-docs-generator.outputPath>
 	</properties>
 
 	<build>
@@ -30,6 +35,36 @@
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-assembly-plugin</artifactId>
 			</plugin>
+			<plugin>
+				<groupId>org.codehaus.mojo</groupId>
+				<artifactId>exec-maven-plugin</artifactId>
+				<executions>
+					<execution>
+						<id>generate-docs</id>
+						<phase>generate-resources</phase>
+						<goals>
+							<goal>java</goal>
+						</goals>
+						<configuration>
+							<mainClass>io.micrometer.docs.DocsGeneratorCommand</mainClass>
+							<includePluginDependencies>true</includePluginDependencies>
+							<arguments>
+								<argument>${micrometer-docs-generator.inputPath}</argument>
+								<argument>${micrometer-docs-generator.inclusionPattern}</argument>
+								<argument>${micrometer-docs-generator.outputPath}</argument>
+							</arguments>
+						</configuration>
+					</execution>
+				</executions>
+				<dependencies>
+					<dependency>
+						<groupId>io.micrometer</groupId>
+						<artifactId>micrometer-docs-generator</artifactId>
+						<version>1.0.1</version>
+						<type>jar</type>
+					</dependency>
+				</dependencies>
+			</plugin>
 			<plugin>
 				<groupId>org.asciidoctor</groupId>
 				<artifactId>asciidoctor-maven-plugin</artifactId>