docs: better "server add" help output

cli/server/add.go

@@ -95,23 +95,19 @@ var serverAddCommand = cli.Command{
 	Description: `
 Add a new server to your configuration so that it can be managed by Abra.
 
-Abra uses the SSH command-line to discover connection details for your server.
-It is advised to configure an entry per-host in your ~/.ssh/config for each
-server. For example:
+Abra relies on the standard SSH command-line and ~/.ssh/config for client
+connection details. You must configure an entry per-host in your ~/.ssh/config
+for each server. For example:
 
-Host example.com example
-  Hostname example.com
-  User exampleUser
-  Port 12345
-  IdentityFile ~/.ssh/example@somewhere
+  Host example.com example
+    Hostname example.com
+    User exampleUser
+    Port 12345
+    IdentityFile ~/.ssh/example@somewhere
 
-Abra can then load SSH connection details from this configuratiion with:
+You can then add a server like so:
 
-    abra server add example.com
-
-Or using the name "example" which is not resolvable on the public Internet:
-
-    abra server add -D example
+  abra server add example.com
 
 If "--local" is passed, then Abra assumes that the current local server is
 intended as the target server. This is useful when you want to have your entire
@@ -119,8 +115,10 @@ Co-op Cloud config located on the server itself, and not on your local
 developer machine. The domain is then set to "default".
 
 You can also pass "--no-domain-checks/-D" flag to use any arbitrary name
-instead of a real domain. Host will be resolved with the "hostname" entry of
-your SSH configuration. Checks for a valid online domain will be skipped.
+instead of a real domain. The host will be resolved with the "Hostname" entry
+of your ~/.ssh/config. Checks for a valid online domain will be skipped:
+
+  abra server add -D example
 `,
 	Flags: []cli.Flag{
 		internal.DebugFlag,
@@ -129,7 +127,7 @@ your SSH configuration. Checks for a valid online domain will be skipped.
 		localFlag,
 	},
 	Before:    internal.SubCommandBefore,
-	ArgsUsage: "<domain>",
+	ArgsUsage: "<name>",
 	Action: func(c *cli.Context) error {
 		if len(c.Args()) > 0 && local || !internal.ValidateSubCmdFlags(c) {
 			err := errors.New("cannot use <domain> and --local together")