If you already have the Prolog extension, sadly it needs to be disabled or uninstalled first because it will override this extension.
Prolog unfortunately chose to have the same file extension as Perl (.pl), and Perl is a built-in language.
so, to make the file show up as Prolog, follow this guide. guide
basically replace their "*.module": "php", with "*.pl": "prolog",
(if the changes don't seem to apply, try reloading VS Code)
After that just install the VS Code extension and the changes will automatically be applied.
What does this do?
This will get you the bleeding-edge syntax highlighting for Prolog. Which means your theme will be able to color your code better.
NOTE: The default VS Code theme does not color much. Switch to the Dark+ theme (installed by default) or use a theme like one of the following to benefit from the changes:
If you'd like to help improve the syntax, take a look at main/main.rb. And make sure to take a look at CONTRIBUTING.md to get a better idea of how code works.