[Epic] Make sure documentation is up-to-date (2019Q2 Edition)

[dhmlau]

Description / Steps to reproduce / Feature proposal

Make sure:

• documentation is up-to-date
  • code exists in documentation is runnable
• apidoc is up-to-date and usable

[loredanacirstea]

At the end of this section: https://loopback.io/doc/en/lb4/HasMany-relation.html#configuring-a-hasmany-relation there are links for create, find, delete, patch - e.g. https://apidocs.strongloop.com/@loopback%2fdocs/repository.html#HasManyRepository.prototype.create.

None of them work anymore (they worked ~2 weeks ago). I did not find the HasManyRepository documentation at all in https://apidocs.strongloop.com/@loopback%2fdocs/repository.html
Has the location changed?

Maybe docs related - I have seen this entry in the changelog: mark HasManyRepository as a readonly property (39227eb) and the subsequent doc change. Is HasManyRepository now only readonly? Asking because I have some issues now with using delete on a _createHasManyRepositoryFactoryFor - though create works, so it is possibly another issue, but I'm mentioning it in case the docs can be made more clearer.

[dhmlau]

@bajtos , it might be related to the clean up work you've done recently on hasMany?

[bajtos]

it might be related to the clean up work you've done recently

Ah, looks like I forgot to list the newly added files in https://github.com/strongloop/loopback-next/blob/master/packages/repository/docs.json

@loredanacirstea would you like to contribute the fix yourself? Compare the list of TS files listed in docs.json with the actual files inside packages/repository/src and add those that are missing.

[dhmlau]

Closing as done.