Cleans up registry subcommand options. (#660)

- Part of #515.
- Order options alphabetically.

## Motivation and Context
See #515.

Sources/ContainerCommands/Network/NetworkDelete.swift

@@ -90,8 +90,8 @@ extension Application {
                 for network in networks {
                     group.addTask {
                         do {
-                            // delete atomically disables the IP allocator, then deletes
-                            // the allocator disable fails if any IPs are still in use
+                            // Delete atomically disables the IP allocator, then deletes
+                            // the allocator. The disable fails if any IPs are still in use.
                             try await ClientNetwork.delete(id: network.id)
                             print(network.id)
                             return nil

Sources/ContainerCommands/Registry/Login.swift

@@ -25,20 +25,23 @@ extension Application {
     public struct Login: AsyncParsableCommand {
         public init() {}
         public static let configuration = CommandConfiguration(
-            abstract: "Login to a registry"
+            abstract: "Log in to a registry"
         )
 
-        @Option(name: .shortAndLong, help: "Username")
-        var username: String = ""
+        @OptionGroup
+        var registry: Flags.Registry
 
         @Flag(help: "Take the password from stdin")
         var passwordStdin: Bool = false
 
-        @Argument(help: "Registry server name")
-        var server: String
+        @Option(name: .shortAndLong, help: "Registry user name")
+        var username: String = ""
 
         @OptionGroup
-        var registry: Flags.Registry
+        var global: Flags.Global
+
+        @Argument(help: "Registry server name")
+        var server: String
 
         public func run() async throws {
             var username = self.username

Sources/ContainerCommands/Registry/Logout.swift

@@ -25,12 +25,12 @@ extension Application {
         public static let configuration = CommandConfiguration(
             abstract: "Log out from a registry")
 
-        @Argument(help: "Registry server name")
-        var registry: String
-
         @OptionGroup
         var global: Flags.Global
 
+        @Argument(help: "Registry server name")
+        var registry: String
+
         public func run() async throws {
             let keychain = KeychainHelper(id: Constants.keychainID)
             let r = Reference.resolveDomain(domain: registry)

Sources/ContainerCommands/Registry/RegistryCommand.swift

@@ -18,15 +18,16 @@ import ArgumentParser
 
 extension Application {
     public struct RegistryCommand: AsyncParsableCommand {
-        public init() {}
         public static let configuration = CommandConfiguration(
             commandName: "registry",
-            abstract: "Manage registry configurations",
+            abstract: "Manage registry logins",
             subcommands: [
                 Login.self,
                 Logout.self,
             ],
             aliases: ["r"]
         )
+
+        public init() {}
     }
 }

Sources/ContainerCommands/Volume/VolumeDelete.swift

@@ -71,8 +71,6 @@ extension Application.VolumeCommand {
                 for volume in volumes {
                     group.addTask {
                         do {
-                            // delete atomically disables the IP allocator, then deletes
-                            // the allocator disable fails if any IPs are still in use
                             try await ClientVolume.delete(name: volume.id)
                             print(volume.id)
                             return nil