GH-695: [Website] Fix anchors on visual identity page

[amoeba]

I think the recent markdown parser change made it so we can't do headers like this anymore,

# Design of the logo {#design}

This fixes the current rendering which has headers that look like this:

Design of the logo {#design}

and restores the internal document anchors. A better solution might be to look into a Jekyll plugin that automatically enables anchors on headers and ToCs.

Closes #695

[github-actions]

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[lidavidm]

Kou filed #695 for this, yeah

[lidavidm]

Are there any other pages that use this?

[amoeba]

Kou filed #695 for this, yeah

Thanks, I missed that. I grepped for {# and didn't see other uses.

[kou]

+1

It may be better that we generate Table of Contents automatically. There is no suitable feature for Jekyll... I may create something later.

Let's use this approach for now.