index.ts is missing from the TypeScript compilation

Description

When trying to consume a module generated by the Swagger-codegen typescript-angular for version 4.3 in a angular 5 project ng serve crashes and says:

ERROR in ./node_modules/petstore-angular4-api/index.ts
Module build failed: Error: C:\angular\petstore-app\node_modules\petstore-angular4-api\index.ts is missing from the TypeScript compilation. Please make sure it is in your tsconfig via the 'files' or 'include' property.
The missing file seems to be part of a third party library. TS files in published libraries are often a sign of a badly packaged library. Please open an issue in the library repository to alert its author and ask them to package the library using the Angular Package Format (https://goo.gl/jB3GVv).
    at AngularCompilerPlugin.getCompiledFile (C:\angular\petstore-app\node_modules\@ngtools\webpack\src\angular_compiler_plugin.js:674:23)
    at plugin.done.then (C:\angular\nils-petstore-app\node_modules\@ngtools\webpack\src\loader.js:467:39)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)

webpack: Failed to compile.

Swagger-codegen version

2.3.1

Swagger declaration file content or url

http://petstore.swagger.io/v2/swagger.json

Command line used for generation

java -jar .\swagger-codegen-cli.jar generate -i http://petstore.swagger.io/v2/swagger.json -l typescript-angular -o C:\angular\petstore-angular4-api

Also tried:
java -jar .\swagger-codegen-cli.jar generate -i http://petstore.swagger.io/v2/swagger.json -l typescript-angular -o C:\angular\petstore-angular527-api -c swagger-codegen-config-angular527.json

where the file swagger-codegen-config-angular527.json contained:
{"ngVersion":"5.2.7"}

Steps to reproduce

1. java -jar .\swagger-codegen-cli.jar generate -i http://petstore.swagger.io/v2/swagger.json -l typescript-angular -o C:\angular\petstore-angular4-api
2. cd C:\angular\petstore-angular4-api
3. npm login
4. npm publish
5. cd C:\angular\petstore-app
6. npm install petstore-angular4-api
7. code .
8. Added to app.module.ts: import { ApiModule } from 'petstore-angular4-api';
9. Added to app.module.ts imports: ApiModule
10. Added to app.compontent.ts: import { PetService} from 'petstore-angular4-api'
11. Added to app.compontent.ts: constructor(private petService: PetService) {}
12. ng serve

Related issues/PRs

None

Suggest a fix/enhancement

Add angular 5 support to Swagger-codegen ?
Add documentation on which parameters are allowed for the parameter ngVersion ?

Start with the generated package's index.ts and the consuming app's app.module.ts and app.component.ts, then reproduce the failure with ng serve using the listed generation commands. Determine whether the generated package can be compiled and published for Angular 5, and document the supported ngVersion values if that is the selected scope.