fix: add bin key back to package.json

[rgant]

PR Checklist

• Addresses an existing open issue: fixes 🐛 Bug: Error: could not determine executable to run #100
• That issue was marked as status: accepting prs
  • I just opened this Issue, and then added a PR to address it.
• Steps in CONTRIBUTING.md were taken

Overview

Re-added the bin key to package.json so that npx package-json-validator works without having to install the package.

Output

$ npx package-json-validator --warnings --recommendations
{ valid: true }

[JoshuaKGoldberg]

Sorry for taking so long - this is perfect! 💯

[JoshuaKGoldberg]

@all-contributors please add @rgant for code.

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[github-actions]

🎉 This is included in version v0.7.1 🎉

The release is available on:

• GitHub releases
• npm package (@latest dist-tag)

Cheers! 📦🚀