[<][<=][=>]GFM extensions to CommonMark

GFM extensions to CommonMark
    Tables
    Checklists
    Strikethrought
    Autolinks
    Disable HTML tags
    Footnotes (no GFM standard)
    Syntax highlighting
    YAML Metadata (unsupported)
    Emojis (unsupported)
    generated footnotes:

[<][<=][=>][*]

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Footnotes (no GFM standard)

Some long sentence. ¹ which is more and more long.