Fix error when rendering fenced code block with wierdly formated dictionary in doc.md file

[PieterCK]

There's an error when one tries to render a dictionary with double curly braces with multiple words inside it inside a fenced code block.

problematic fenced code block if used in API doc markdown:

 {
    "id": {{ json issue }},
  }

this block is rendered properly in the API doc markdown:

 {
    "id": {{ issueId }},
    "json": {{ json }}
  }

error screen shot:

error from lint:

CZO thread

[zulipbot]

Hello @zulip/server-api members, this issue was labeled with the "area: documentation (api and integrations)" label, so you may want to check it out!

[rs545837]

@zulipbot claim