fix: download-sources takes lookaside cache locations

Author: Antonio Salinas

docs/user/reference/cli/azldev.md

@@ -5,6 +5,7 @@ package advanced
 
 import (
 	"github.com/microsoft/azure-linux-dev-tools/internal/app/azldev"
+	"github.com/microsoft/azure-linux-dev-tools/internal/app/azldev/cmds/downloadsources"
 	"github.com/spf13/cobra"
 )
 
@@ -23,7 +24,12 @@ output but fully supported.`,
 	}
 
 	app.AddTopLevelCommand(cmd)
+	downloadSourcesOnAppInit(app, cmd)
 	mcpOnAppInit(app, cmd)
 	mockOnAppInit(app, cmd)
 	wgetOnAppInit(app, cmd)
 }
+
+func downloadSourcesOnAppInit(app *azldev.App, parentCmd *cobra.Command) {
+	downloadsources.OnAppInit(app, parentCmd)
+}