Why use so many levels of markdown headers? That prevents pasting parts of changelog as a section of another document (e.g. release notes), creates cacophony of fonts when converted to html, and is overall unnecessary because it adds no meaning nor reading convenience. It looks like this guy is overcomplicating quite a simple thing.

I've been maintaining changelogs for pretty much all my career, in simpler format:

    - at the top of file go unreleased changes, without a header

    1.6.1: 2005-01-22
    - fixed: one
    - fixed: another

    1.6: 2004-11-18
    - fixed: this
    - added: that
    - redesigned preferences dialog

There is zero markup noise here, and when interpreted as markdown it looks just as nice.