Fixes backlink to earlier chapter

[hlapp]

I actually am not sure that this is indeed the correct fix (it seems this is what other chapters with back or forward references do). The original link, however, results in a 404.

[tobyhodges]

Thank you for bring this up, @hlapp. I tried building the pages locally and it did not seem like your approach worked (perhaps because the Backwards Design section is an anchor within a larger page?) but I have suggested the corrected URL. If you commit that suggestion, I will merge this and that should fix the link.

[hlapp]

@tobyhodges do you know where we could find the piece of template or code that renders the link? Perhaps there is actually a mechanism for linking to in-page anchors. Though I suspect you're right that there isn't.

[tobyhodges]

I did not previously know. But your question sent me looking and, indeed, the Bookdown documentation suggests that the kind of cross-referencing you were trying to use should work: https://bookdown.org/yihui/bookdown/cross-references.html

However, the change you made definitely did not in my local build. I have just tried using the [earlier chapter](#backward-design) approach, and that did work! I will update my suggested change again to reflect this.

[hlapp]

Awesome @tobyhodges, just committed it.

[tobyhodges]

Thank you @hlapp