Remove reference to yalc repository on geppetto-showcase

The following (local) yalc references should be replaced with references to the proper npm package on the npm registry
https://github.com/MetaCell/geppetto-meta/blob/development/geppetto-showcase/package.json#L59-L61

Open geppetto-showcase/package.json at lines 59-61 and inspect the dependency references. Replace the local yalc references with the proper npm registry package references, then verify the package file no longer points to the yalc repository.

Written by the indexing model from the issue text.