Correct Inv App Folder Location

[echads]

I can send PR or just take a look and do self. :-)

echads@4015446

Originally readme said it was in the unpublishedScripts folder, looks like it is in the /vircadia/scripts/system/inventory/ folder now.

community-apps/applications/inventory-app/README.md

# inventory

This app is managed in the main project-athena repo for Vircadia. Please see the /vircadia/scripts/system/inventory/ folder for its source and make PRs against that for any changes.

- https://github.com/vircadia/vircadia/tree/master/scripts/system/inventory