Feature/typescript support

[allohamora]

This PR:

• adds TypeScript support based on JSDoc comments
• generates correct package-lock by npm i
• fixes npm vulnerabilities by npm audit fix

Notes:

• If you create an index.d.ts file that imports the same modules as index.js like here, it will work locally, but it won’t work when the package is installed from npm

Package to test locally:

npm i test-solidgate-node-sdk-ts

Screenshot: