updated README on how to use JFR based agent profiler

README.md

@@ -1,18 +1,29 @@
 # Pyroscope Java agent
 
-The Java profiling agent for Pyroscope.io. Based on [async-profiler](https://github.com/jvm-profiling-tools/async-profiler).
+The Java profiling agent for Pyroscope.io. Based
+on [async-profiler](https://github.com/jvm-profiling-tools/async-profiler).
 
 ## Distribution
 
 The agent is distributed as a single JAR file `pyroscope.jar`. It contains native async-profiler libraries for:
+
 - Linux on x64;
 - Linux on ARM64;
 - MacOS on x64.
 - MacOS on ARM64.
 
+## Windows OS support
+
+It also contains support for Windows OS, through JFR profiler. In order to use JFR as profiler in place of
+async-profiler,
+you need to configure profiler type, either through configuration file or environment variable.
+
+By setting `PYROSCOPE_PROFILER_TYPE` configuration variable to `JFR`, agent will use JVM built-in profiler.
+
 ## Downloads
 
-Visit [releases](https://github.com/pyroscope-io/pyroscope-java/releases) page to download the latest version of `pyroscope.jar`
+Visit [releases](https://github.com/pyroscope-io/pyroscope-java/releases) page to download the latest version
+of `pyroscope.jar`
 
 ## Usage