chore: set which files deploy to npm

[ert78gb]

I think good practice to publish only the files that needed. The unpacked size changes from 66.8 kB to 29.6 kB.

the result of the npm pack command

Before

npm notice npm notice 📦 szamlazz.js@6.0.0 npm notice === Tarball Contents === npm notice 526B .github/workflows/ci.yml npm notice 2.8kB CHANGELOG.md npm notice 1.1kB LICENSE npm notice 5.6kB README.md npm notice 470B index.js npm notice 2.2kB lib/Buyer.js npm notice 6.2kB lib/Client.js npm notice 2.9kB lib/Constants.js npm notice 4.1kB lib/Invoice.js npm notice 3.4kB lib/Item.js npm notice 698B lib/Seller.js npm notice 2.0kB lib/XMLUtils.js npm notice 861B package.json npm notice 2.5kB tests/buyer.spec.js npm notice 7.1kB tests/client.spec.js npm notice 2.4kB tests/invoice.spec.js npm notice 3.7kB tests/item.spec.js npm notice 2.6kB tests/resources/setup.js npm notice 242B tests/resources/success_with_pdf.xml npm notice 218B tests/resources/success_without_pdf.xml npm notice 259B tests/resources/unknown_invoice_number.xml npm notice 13.9kB tests/resources/xmlszamla.xsd npm notice 848B tests/seller.spec.js npm notice === Tarball Details === npm notice name: szamlazz.js npm notice version: 6.0.0 npm notice filename: szamlazz.js-6.0.0.tgz npm notice package size: 14.9 kB npm notice unpacked size: 66.8 kB npm notice shasum: 1bfc4c062ec24463fa605b31e613ac4ed4f2ac55 npm notice integrity: sha512-h4ycd7Yy0NZA3[...]Vh9qj+ZFhPa9g== npm notice total files: 23 npm notice szamlazz.js-6.0.0.tgz

After

npm notice npm notice 📦 szamlazz.js@6.0.0 npm notice === Tarball Contents === npm notice 1.1kB LICENSE npm notice 5.6kB README.md npm notice 470B index.js npm notice 2.2kB lib/Buyer.js npm notice 6.2kB lib/Client.js npm notice 2.9kB lib/Constants.js npm notice 4.1kB lib/Invoice.js npm notice 3.4kB lib/Item.js npm notice 698B lib/Seller.js npm notice 2.0kB lib/XMLUtils.js npm notice 906B package.json npm notice === Tarball Details === npm notice name: szamlazz.js npm notice version: 6.0.0 npm notice filename: szamlazz.js-6.0.0.tgz npm notice package size: 8.3 kB npm notice unpacked size: 29.6 kB npm notice shasum: b6ea7c5757396ce41f39ca6b4a67447e17475c14 npm notice integrity: sha512-pyAeiTUg8bhPa[...]SrEAXjdXnqCQA== npm notice total files: 11 npm notice szamlazz.js-6.0.0.tgz