tour: Resize handles broken

[matthewCmatt]

Context: https://go.dev/tour/welcome/1

It seems like the different panes of the Tour of Go are intended to be resizeable. When hovering over the border, the mouse cursor changes to move, but on clicking and dragging on the handles doesn't seem to do anything.

Screen.Recording.2025-02-27.at.10.57.53.AM.mov

Observed on Chromium, Safari, and Firefox on MacOS.

Keywords: gutter, handle, resize, pane, split, split.js

[matthew-myers-boseprofessional]

I observed the same on Windows 11 with Firefox and Chrome.