Info strings for suffixed headings

[Crissov]

One benefit is that it makes existing attribute extensions partially compatible if written in a specific way: consider curly braces optional wrappers around indo strings, but required in places where info strings are otherwise impossible or for line breaks inside.

## Heading ## {info string within optional wrappers} 

![text](target "title" {info string within optional wrappers}) or 
![text](target {"title" info string within optional wrappers})

[label] 

  label: <target> {info string within optional wrappers} 

``` {info string within optional wrappers} 
```

Info strings elsewhere

## Heading # still heading ## Heading ## info string ## Heading ### still heading ## Heading## still heading ## Heading ##still heading ## Heading # # still heading Babelmark In the Github issue I’m requesting a small syntax change to enable info strings, as known from fenced code blocks, for suffixed ATX headings. I believe they are the perfect entry point for many kinds of extensions. Even if not parsed further, info strings can be considered comments that will not appear in the output. I …