"experimental-features": ["LetUnwrap"], causes a panic

[DZakh]

I added "experimental-features": ["LetUnwrap"], to my rescript.json, which results in:

thread 'main' (260424472) panicked at src/watcher.rs:84:14:
Can't initialize build: Could not read rescript.json at /Users/dzakh/code/envio/ui
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 ELIFECYCLE  Command failed with exit code 101.

[DZakh]

Figured it out that it should be

"experimental-features": {
    "LetUnwrap": true
  },

but still I'll keep an issue here