* feat: add index-name option to cli

* feat(serve): update serve command to serve index

* feat(locales): update translations

* fix(gulp): downgrade gulp to 3.9.0, buggy 3.9.1

* build(CI): seems node11 natives need to update

Bumps [js-yaml](https://github.com/nodeca/js-yaml) from 3.12.1 to 3.13.1.
- [Release notes](https://github.com/nodeca/js-yaml/releases)
- [Changelog](https://github.com/nodeca/js-yaml/blob/master/CHANGELOG.md)
- [Commits](nodeca/js-yaml@3.12.1...3.13.1)

Signed-off-by: dependabot[bot] <[email protected]>

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.11 to 4.17.15.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.11...4.17.15)

Signed-off-by: dependabot[bot] <[email protected]>

Bumps [eslint](https://github.com/eslint/eslint) from 3.19.0 to 4.18.2.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/master/CHANGELOG.md)
- [Commits](eslint/eslint@v3.19.0...v4.18.2)

Signed-off-by: dependabot[bot] <[email protected]>

Bumps [mixin-deep](https://github.com/jonschlinkert/mixin-deep) from 1.3.1 to 1.3.2.
- [Release notes](https://github.com/jonschlinkert/mixin-deep/releases)
- [Commits](jonschlinkert/mixin-deep@1.3.1...1.3.2)

Signed-off-by: dependabot[bot] <[email protected]>

* feat: show up help if no args were passed

closes #71

* chore: update warning message

* chore: minor tweak

fix locales epilog link to docsifyjs

* fix: warn on unknown commands

* feat: suggest matching commands

fix: npm audit issues