Also, fix README

[openalex] make search act similar to the one on openalex web

See merge request !425

Port all the tasty specs to hspec

See merge request !423

See #490

Resolve "Error uploading zip file on dev"

See merge request !417

However, develop still doesn't work well

Fix bug in DB transaction rollbacks in the presence of domain-specific errors

Closes #480

See merge request !420

This commit fixes the bug with DbTx rollbacks and domain-specific
errors. What we do now is throwing an exception during the evaluation of
`DbFail`, to later catch it _after_ `withTransactionM` has performed a
clean rollback, and only at that point we call `throwError`.

This also means that we need to catch `DbTx` errors via the `MonadError`
interface, not via the exception-handling interface, to get proper
rollback behavior.

errorWith has a `HasNodeError` constraint but the name was misleading.

This means, of course, that now rollback tests are failing, but that's
fine, we can then fix things properly in the DbTx code.

Have `extractNgramsFromDocument` catch the right exception in case extraction fails

Closes #481

See merge request !419

[graphql] get contexts for ngrams fix

See merge request !416

Resolve "API refactorings"

See merge request !412