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

.gitignore

@@ -1,3 +1,4 @@
 public
 resources
-assets/jsconfig.json
+assets/jsconfig.json
+.hugo_build.lock