chore: added doc to README.md

Signed-off-by: Bernd Warmuth <bernd.warmuth@dynatrace.com>

Author: Bernd Warmuth

README.md

@@ -215,6 +215,16 @@ Once you've added a hook as a dependency, it can be registered at the global, cl
           FlagEvaluationOptions.builder().hook(new ExampleHook()).build());
 ```
 
+### Tracking
+
+The [tracking API](https://openfeature.dev/specification/sections/tracking/) allows you to use OpenFeature abstractions to associate user actions with feature flag evaluations.
+This is essential for robust experimentation powered by feature flags.
+
+```java
+OpenFeatureAPI api = OpenFeatureAPI.getInstance();
+api.getClient().track("visited-promo-page", new MutableTrackingEventDetails(99.77).add("conurrencyCode", "USD"))
+```
+
 ### Logging
 
 The Java SDK uses SLF4J. See the [SLF4J manual](https://slf4j.org/manual.html) for complete documentation.