build script fails

the npm build task runs tsc.
tsc complains it can't find nothing to compile (no tsconfig)
```
$ npm run build

> @ build C:\Users\Pascal\code\boba-js
> tsc

Version 3.8.3
Syntax:   tsc [options] [file...]

Examples: tsc hello.ts
          tsc --outFile file.js file.ts
          tsc @args.txt
          tsc --build tsconfig.json

```