This PR fixes and issue where generating Nest app in the new TS setup
results in a build error due to missing `experimentalDecorators` option
in tsconfig. Decorators are required for Nest to work, but we do not set
it anymore in `tsconfig.base.json` by default.
## Current Behavior
Nest apps are broken
## Expected Behavior
Nest apps work
## Related Issue(s)
<!-- Please link the issue being fixed so it gets closed when this is
merged. -->
Fixes #
a0cfe88f5f