Add Command.options property, and make it and Command.commands readonly (#47)

Author: shadowspawn

index.d.ts

@@ -453,7 +453,8 @@ export class CommanderError extends Error {
   export class Command<Args extends any[] = [], Opts extends OptionValues = {}> {
     args: string[];
     processedArgs: Args;
-    commands: CommandUnknownOpts[];
+    readonly commands: readonly CommandUnknownOpts[];
+    readonly options: readonly Option[];
     parent: CommandUnknownOpts | null;
 
     constructor(name?: string);

tests/commander.test-d.ts

@@ -40,7 +40,8 @@ expectType<commander.Argument>(commander.createArgument('<foo>'));
 expectType<string[]>(program.args);
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 expectType<[]>(program.processedArgs);
-expectType<commander.CommandUnknownOpts[]>(program.commands);
+expectType<readonly commander.CommandUnknownOpts[]>(program.commands);
+expectType<readonly commander.Option[]>(program.options);
 expectType<commander.CommandUnknownOpts | null>(program.parent);
 
 // version