rocket-51-docs-theme-launch fails to install

When choosing a Documentation Website (@rocket/launch theme), the generated package.json refers to "@rocket/launch": "0.21.4" , but latest @rocket/launch is 0.21.3: https://www.npmjs.com/package/@rocket/launch

So simply `npm install` fails to launch

## Reproduction steps:
1) npx @rocket/create@latest
2) Choose "Documentation Website" for starter template
3) follow the rest of the guides