feat: Working on command-line documentation.

Sources/BumpVersion/Application.swift

@@ -0,0 +1,19 @@
+import ArgumentParser
+import Foundation
+
+@main
+struct Application: AsyncParsableCommand {
+  static let commandName = "bump-version"
+
+  static let configuration: CommandConfiguration = .init(
+    commandName: commandName,
+    version: VERSION ?? "0.0.0",
+    subcommands: [
+      BuildCommand.self,
+      BumpCommand.self,
+      GenerateCommand.self,
+      ConfigCommand.self
+    ],
+    defaultSubcommand: BumpCommand.self
+  )
+}