Preinstall command in README doesn't work on windows #24

The preinstall command specified in the README:
"preinstall": "command -v link-module-alias && link-module-alias clean || true"
does not work on Windows as command is not a Windows command.

You can achieve the same effect cross platform with npm list, albeit more slowly:
"preinstall": "npm list link-module-alias && link-module-alias clean || true".

Would you consider updating the command to help others avoid this?