Code formatting not respecting indentation

I have the following Markdown code:

```
{
"name": "",
"description": ""
"entries": [{

}]
]
```
This formats correctly in GitHub issue tracker, but not in Macdown. The attached image illustrates the behaviour


MacDown 0.7.1, macOS 10.13.1

Reproduce the issue in MacDown 0.7.1 on macOS 10.13.1 using the indented fenced Markdown example from the report, and compare its rendering with GitHub's. Trace the Markdown code-formatting path from that reproduction; done means the indentation and nested content render as expected.

Written by the indexing model from the issue text.