doc: update README

[skip_ci]

README.md

@@ -8,11 +8,13 @@ Status: _beta_. Current functionality works, but needs more user testing and pol
 
 ## Requirements and installation
 
-Solarpos is a Java application, requiring Java 21 or newer. See the [latest release](https://github.com/klausbrunner/solarpos/releases/latest) or build from source using `mvn package`.
+Solarpos is a Java application, requiring a Java 21 or newer runtime. See the [latest release](https://github.com/klausbrunner/solarpos/releases/latest) or build from source using `mvn package`. 
+
+The release artifact is a single JAR file that requires no "installation". If you're unsure how to get a Java runtime for your system, [Adoptium](http://adoptium.net/) is recommended.
 
 ### Native builds
 
-Native builds are available for some platforms. These do not require a Java runtime and can be used stand-alone, like any other native application.
+Native builds are available for some major platforms. These do not require a Java runtime and consist of a single, stand-alone executable that can be used as is.
 
 ### macOS: Homebrew installation