Cannot run watch-demo after following setup

[mojoee]

Description of the setup:
I am running the repository inside a virtualenv where I installed the following packages, all with scoop:
7zip v19.00
nodejs v9.11.2
nvm v1.1.7
yarn v1.22.4

I installed yarn and the right java dependencies. However, I cannot run the watch-demo command as described in the github. After trying all combinations of the ./watch-demo I get the following error:

'.\watch-demo' is not recognized as an internal or external command, operable program or batch file.

Is there anything I am missing?