refactor: improved dx, typed library, comments

[a-rustacean]

I refactored the code, improved the readme, eliminated the deprecated request dependency, introduced axios due to its larger community, incorporated JSDoc comments, eliminated unnecessary recursion, utilized modern and efficient language features like Promise.all, excluded node_modules as it's not necessary for npm, provided a custom domain option for TempMail (#7 was unnecessary), and introduced eslint, prettier, husky, lint-staged, and npm-scripts to enhance the developer experience.

[Jon-Becker]

Hey! I got your email. I don't check this repository too often for PRs, but I will in the future.

I'll review this today and merge it in if all is well. I'll also probably set up a test suite, and add other services so that the library works with more than one temp mail service.

Thank you for your contribution, I appreciate it!

[Jon-Becker]

Looks good, but please don't remove preview.png, its used by some external services I believe. I can make the npm module ignore it though.

I'll also make a few changes here before merging.

[a-rustacean]

Certainly, I've readded the preview.png file as per your request. Thank you for your quick response and assistance!

[a-rustacean]

Could you kindly review the changes I've made?

[Jon-Becker]

i'll make a release after testing thoroughly :)

if you would like to be made a contributor here, since I don't manage this repo much, let me know!

[a-rustacean]

I'd be happy to be a contributor.