Workshop venue field

Currently the workshops at COLING 2020 list COLING as a venue, e.g.: https://www.aclweb.org/anthology/volumes/2020.dmr-1/

This gives the impression that is a *joint* event and should be cited as COLING-DMR, which is incorrect.

(Also came up in #1069. Maybe a problem with the ingestion process?)

If we want to list the main conference of a workshop or secondary conference, perhaps this should be a separate field?

首先检查 2020.dmr-1 的 workshop 数据以及生成其 COLING venue 的 ingestion 流程，然后查看 issue #1069 中的相关讨论。完成应意味着该 workshop 不再被呈现为 COLING 联合活动，并且其引用反映正确的 venue，同时明确对父级会议的处理方式。

由索引模型根据 Issue 内容生成。