docs: sdkman install instructions

Author: MykolaGolubyev

webtau-docs/pre-filter/installation-groovy-runner.md

@@ -4,5 +4,11 @@ If you have [brew](https://brew.sh) installed in your system use
 brew install testingisdocumenting/brew/webtau
 ```
 
+If you have [sdkman](https://sdkman.io) installed in your system use
+
+```
+sdk install webtau
+```
+
 Alternatively, download and unzip [webtau](https://repo.maven.apache.org/maven2/org/testingisdocumenting/webtau/webtau-dist/${project.version}/webtau-dist-${project.version}-webtau.zip). 
 Add it to your `PATH`.