List languages

Creates a document of the team from a file, owned by the account of the key, with one translation per target language. The file is checked at once (format, size, readable content), but its text is indexed afterwards: the document answers with status `UPLOADED` and no `wordCount`. Poll `GET /v1/documents/{id}` until the status is `INDEXED`, when the translation can start, or `INDEXING_ERROR`, when the file could not be processed. The body is `multipart/form-data`: `file` holds the document, the other parts are text, and `targetLanguages` is a JSON array, sent either as a text field or as an `application/json` part with a filename (e.g. `curl -F 'targetLanguages=@langs.json;type=application/json'`). Each target language lists the email addresses of its translators, possibly none. An address of a member of the team (a manager, the caller included, or a translator) is assigned as it is. Any other address is invited to the team as a translator, within the translator seats of the plan, and receives the invitation by email. A translator invited by a call that fails later stays invited.