Update instructions on how to launch jar file, suggest terminal

.github/resources/preview_notes.md

@@ -4,6 +4,7 @@
 
 ## What to Download
 
-- If you already have a compatible Java runtime installed (Java 11 or later), you can just download the executable cross-platform Jar file, and should be able to run it by double-clicking.
+- If you already have a compatible Java runtime installed (Java 11 or later), you can just download the executable cross-platform Jar file, and should be able to run it by executing (in a shell window that is operating in the same directory you placed the downloaded the Jar file):
+  java -jar _jar-file-name_
 - If you are on a Mac, unfortunately something has broken down between OpenJDK and Apple which prevents code-signed, notarized disk images from being built successfully, so unless and until that can be resolved, you will need to use the cross-platform jar file as described above. You can install the Java distribution used by Deep Symmetry from [here](https://docs.aws.amazon.com/corretto/latest/corretto-17-ug/downloads-list.html). Be sure to choose the correct version for your processor, either [macOS aarch64 (for Apple Silicon)](https://corretto.aws/downloads/latest/amazon-corretto-17-aarch64-macos-jdk.pkg) or [macOS x64 (for Intel)](https://corretto.aws/downloads/latest/amazon-corretto-17-x64-macos-jdk.pkg).
 - If you are on 64-bit Windows and don’t want to have to separately install Java you can download the Win64 MSI installer (`.msi` file), which installs a Windows application with the Java runtime built in.