Add collapsible sections, sticky version header, and style refinement…

…s for changelog highlights

release: v1.1.36

release: v1.1.35

release: v1.1.34

release: v1.1.33

release: v1.1.32

release: v1.1.31

release: v1.1.30

release: v1.1.29

release: v1.1.28