knowledgeDocumentCard: fix table of content collapsing
knowledgeDocumentCard: fix table of content collapsing

We should not consider the table of contents as part of the min width
of the document card, as the document card can display in a collapsed
mode without the toc.
[endlessm/eos-sdk#3667]

endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib