[mst-content-hint] Pull Request: chore: fix ReSpec markdown error

sidvishnoi has just submitted a new pull request for https://github.com/w3c/mst-content-hint:

== chore: fix ReSpec markdown error ==
There have been some changes in markdown processing, which are incompatible with this document. Also, markdown is not used in the document, so removing it.

As an add-on, changed ReSpec script to lite jQuery-less version.

See https://github.com/w3c/mst-content-hint/pull/34