chore: don't pack `test/` folder and other dev files

[mvayngrib]

currently this package includes a bunch of dev/test files

Test Plan

run npm pack. You should see only these files listed in tarball contents

npm notice === Tarball Contents === 
npm notice 578B  .github/FUNDING.yml
npm notice 4.5kB CHANGELOG.md       
npm notice 2.5kB README.md          
npm notice 103B  index.js           
npm notice 4.6kB lib/parse.js       
npm notice 4.3kB lib/stringify.js   
npm notice 1.6kB package.json