update ToC

[biumiamy]

• current ToC doesnt show the headlines per chapter very well (example here)

• need to expand manually to see.. even when scrolled past it already

• example of JOVI article shows headlines and then expands sub headlines gradually

[biumiamy]

• add audio
• video
• ...

[biumiamy]

(I wrote a link in the wrong issue)

[biumiamy]

still missing: color-coding for hermeneutics layer and then a question: should it collapse if it's the H-layer?

[biumiamy]

@danieleguido When scrolling, currently not visible where the scrolling position is - should show current position in bold

[eliselavy]

@danieleguido scrolling need to be added - can not use the guidelines

[eliselavy]

Available in production https://github.com/C2DH/journal-of-digital-history/releases/tag/v4.4.1