Add micrometer library doc (#9856)

Author: trask

.github/scripts/markdown-link-check-config.json

@@ -16,6 +16,9 @@
     },
     {
       "pattern": "^http(s)?://logback\\.qos\\.ch"
+    },
+    {
+      "pattern": "^https://micrometer\\.io"
     }
   ]
 }

instrumentation/micrometer/micrometer-1.5/README.md instrumentation/micrometer/micrometer-1.5/javaagent/README.md

@@ -0,0 +1,38 @@
+# Micrometer Instrumentation for Micrometer version 1.5 and higher
+
+This module provides a [Micrometer registry](https://micrometer.io/docs/concepts#_registry) which
+sends Micrometer metrics to the
+[OpenTelemetry Metrics SDK](https://github.com/open-telemetry/opentelemetry-java/tree/main/sdk/metrics).
+
+## Quickstart
+
+### Add these dependencies to your project
+
+Replace `OPENTELEMETRY_VERSION` with the [latest
+release](https://search.maven.org/search?q=g:io.opentelemetry.instrumentation%20AND%20a:opentelemetry-micrometer-1.5).
+
+For Maven, add to your `pom.xml` dependencies:
+
+```xml
+<dependencies>
+  <dependency>
+    <groupId>io.opentelemetry.instrumentation</groupId>
+    <artifactId>opentelemetry-micrometer-1.5</artifactId>
+    <version>OPENTELEMETRY_VERSION</version>
+  </dependency>
+</dependencies>
+```
+
+For Gradle, add to your dependencies:
+
+```groovy
+implementation("io.opentelemetry.instrumentation:opentelemetry-micrometer-1.5:OPENTELEMETRY_VERSION")
+```
+
+### Usage
+
+The instrumentation library provides an implementation of `MeterRegistry` to bridge Micrometer API to OpenTelemetry Metrics.
+
+```java
+MeterRegistry meterRegistry = OpenTelemetryMeterRegistry.builder(openTelemetry).build();
+```