feat(article): Scrollspy for the table of contents (#425)

* Add first try at scrollspy (broken right now)

* Scrollspy actually works now

* Fix VS Code errors by setting JS version

* Recompute offsets when window size changes

* Improve list compatibility for toc active selection

Support up to 6 levels of indentation, properly support <ol>

* Remove debug string

* Add more docs in smoothAnchors

* Use a map to match ids to navigation elements

assets/scss/partials/base.scss

@@ -1,7 +1,6 @@
 html {
     font-size: 62.5%;
     overflow-y: scroll;
-    scroll-behavior: smooth;
 }
 
 * {