This PR changes the root `package.json` to use a scoped name when using
`create-nx-workspace`. This was already done in most presets, but we
missed the old "package-based" setup.
e.g. These
```
create-nx-workspace acme --preset=ts
create-nx-workspace acme --preset=npm
```
Should all result in `@acme/source` being used in root `package.json`,
not `acme`. The scope will be used when generating projects if the user
doesn't pass `--importPath`.
f22c63de2d