fix: skip attrsets in patterns

[fgaz]

Fixes parsing of docs in this kind of code:

{ 
  pkgs ? import <nixpkgs>
    # | This attrset must be skipped -- it is not the top-level attrset
    # ↓ even though it comes first!
    {   }
}:

{
  /** 
    This binding is in the top-level attrset
  */
  iAmTopLevel = null;
}

[infinisil]

Awesome, thanks for writing the test and giving a nice explanation of the problem!

[fgaz]

@infinisil could you tag a new release so we get the fix in nixpkgs?

[infinisil]

@hsjobeki Could you do the release?

[fgaz]

Thank you!