Those docs need a web server to run, because they’re actually generated dynamically! Running zig std will spin up a local web server and open it in your web browser and you’ll be able to browse the same docs as on Zig Documentation
As long as zig std prints the address it’s listening on, you should be able to view the docs by navigating to that address in a browser. It also tries to open your web browser automatically, which might result in printing error: FileNotFound if it can’t find the command to do so, but that won’t affect the core behavior of the server.