fix: export main

Author: jdx

src/index.ts

@@ -3,6 +3,7 @@ import * as Config from '@anycli/config'
 import Command from './command'
 import * as flags from './flags'
 export {parse} from '@anycli/parser'
+export {Main} from './main'
 
 export default Command
 export {

src/main.ts

@@ -2,7 +2,7 @@ import * as Config from '@anycli/config'
 
 import {Command} from '.'
 
-export default class Main extends Command {
+export class Main extends Command {
   static parserOptions = {'--': false, strict: false}
 
   static run(argv = process.argv.slice(2), opts?: Config.Options) {