formatting CI badges fails

[eahanson]

A readme.md file containing:

[![CI](https://github.com/synchronal/pages/actions/workflows/tests.yml/badge.svg "CI")](https://github.com/synchronal/pages/actions)

fails with:

** (FunctionClauseError) no function clause matching in MarkdownFormatter.Renderer.render/3    
    
    The following arguments were given to MarkdownFormatter.Renderer.render/3:
    
        # 1
        {"img", [{"src", "https://github.com/synchronal/pages/actions/workflows/tests.yml/badge.svg"}, {"alt", "CI"}, {"title", "CI"}], [], %{}}
    
        # 2
        Q.new([])
    
        # 3
        %MarkdownFormatter.Renderer.RenderState{class: nil, depth: 0, line_length: 120, parent: nil, prefix: ""}
    
    Attempted function clauses (showing 10 out of 29):
    
        defp render([], doc, _opts)
        defp render(contents, doc, %{class: class} = opts) when not (class == nil)
        defp render({"h1", attrs, contents, %{}}, doc, opts)
        defp render({"h2", attrs, contents, %{}}, doc, opts)
        defp render({"h3", attrs, contents, %{}}, doc, opts)
        defp render({"h4", attrs, contents, %{}}, doc, opts)
        defp render({"h5", attrs, contents, %{}}, doc, opts)
        defp render({"h6", attrs, contents, %{}}, doc, opts)
        defp render({"p", [], contents, %{}}, doc, opts)
        defp render({"blockquote", [], contents, %{}}, doc, opts)
        ...
        (19 clauses not shown)
    
    lib/markdown_formatter/renderer.ex:88: MarkdownFormatter.Renderer.render/3
    lib/markdown_formatter/renderer.ex:168: MarkdownFormatter.Renderer.render/3
    lib/markdown_formatter/renderer.ex:130: MarkdownFormatter.Renderer.render/3
    lib/markdown_formatter/renderer.ex:169: MarkdownFormatter.Renderer.render/3
    lib/markdown_formatter/renderer.ex:115: MarkdownFormatter.Renderer.render/3
    lib/markdown_formatter/renderer.ex:169: MarkdownFormatter.Renderer.render/3
    lib/markdown_formatter/renderer.ex:81: MarkdownFormatter.Renderer.to_markdown/2
    (mix 1.13.4) lib/mix/tasks/format.ex:564: Mix.Tasks.Format.format_file/2

[gaggle]

I seem to be getting this when using the collapsible syntax (<detail></detail>) and references ([foo]: https://example.com]) too.

[sax]

Oof. For some reason I never saw this issue.

Fixing the original issue is trivial; I just shipped 04b1f49 to deal with it.

Collapsible... probably will be fine. References, though. That... hm. I'm going to open separate issues to track those.

[sax]

Just added #2 for collapsible and #3 to track reference links. @gaggle I'm going to try to knock out collapsible this morning, but will have to come back to references after work, or before work on another day.

[sax]

This original issue should be fixed in v0.6.0. Let me know if you continue to have issues, and for new unhandled syntax feel free to open new issues!