Revert "Remove explicit formatting from command signature options"

This reverts commit c3aba72 as this is needed to have the option values default to null while giving the documented value of the inferred values.

packages/framework/src/Console/Commands/ServeCommand.php

@@ -22,7 +22,7 @@
 class ServeCommand extends Command
 {
     /** @var string */
-    protected $signature = 'serve {--host=localhost} {--port=8080}';
+    protected $signature = 'serve {--host= : <comment>[default: "localhost"]</comment>}} {--port= : <comment>[default: 8080]</comment>}';
 
     /** @var string */
     protected $description = 'Start the realtime compiler server.';