Remove `src` folder of npm package

[mbpictures]

Hi!

I'm using dodopayment in a NestJS server. However, the published package still contains the src-Folder instead of the transpiled code only. This leads to several compilation errors while building NestJS. Removing the src Folder works for me. As all required files (type definitions and JavaScript) are included as well, the src folder should not be required to be published to npm. I suggest ignoring it