feat: Begins vault commands, adds nodes for rendering discussion documentation.

Sources/hpa/VaultCommands/VaultOptions.swift

@@ -0,0 +1,31 @@
+import ArgumentParser
+
+// Holds the common options for vault commands, as they all share the
+// same structure.
+@dynamicMemberLookup
+struct VaultOptions: ParsableArguments {
+
+  @OptionGroup var globals: BasicGlobalOptions
+
+  @Option(
+    name: .shortAndLong,
+    help: "The vault file path.",
+    completion: .file()
+  )
+  var file: String?
+
+  @Argument(
+    help: "Extra arguments to pass to the vault command."
+  )
+  var extraArgs: [String] = []
+
+  subscript<T>(dynamicMember keyPath: WritableKeyPath<BasicGlobalOptions, T>) -> T {
+    get { globals[keyPath: keyPath] }
+    set { globals[keyPath: keyPath] = newValue }
+  }
+
+  subscript<T>(dynamicMember keyPath: KeyPath<BasicGlobalOptions, T>) -> T {
+    globals[keyPath: keyPath]
+  }
+
+}