refactor: domainName as arg and doc strings

See coop-cloud/organising#163.

cli/server/remove.go

@@ -1,8 +1,6 @@
 package server
 
 import (
-	"errors"
-
 	"coopcloud.tech/abra/cli/internal"
 	"coopcloud.tech/abra/pkg/client"
 	"github.com/sirupsen/logrus"
@@ -19,13 +17,14 @@ internal bookkeeping so that it is not managed any more.
 `,
 	HideHelp: true,
 	Action: func(c *cli.Context) error {
-		server := c.Args().First()
-		if server == "" {
-			internal.ShowSubcommandHelpAndError(c, errors.New("no server provided"))
-		}
-		if err := client.DeleteContext(server); err != nil {
+		domainName := internal.ValidateDomain(c)
+
+		if err := client.DeleteContext(domainName); err != nil {
 			logrus.Fatal(err)
 		}
+
+		logrus.Infof("Server at '%s' has been forgotten", domainName)
+
 		return nil
 	},
 }