Change working directory to project root instead of dev_cmds directory

[PatrickLehnerXI]

The working directory seems to be set to the dev_cmds/ directory, not to the project root. This doesn't seem very useful, since I usually want to interact with other project files, and comparatively rarely with other devcmds.
In particular, this behavior is different from yarn/npm scripts and other task runners.

Note: This feedback was provided internally at XITASO, so I'm creating this issue for tracking.