docs: middle mouse click opens editor example instead of docs in new tab

[MarcBaeuerle]

PR Description

Clicking on <a> tags with the middle mouse button always opens them in a new tab.
Currently, they open /docs.{page}.html# since the href link and onclick link are different.

Checklist

• This PR is atomic (i.e., it fixes one issue at a time).
• The title is a concise semantic commit message (e.g. "fix: correctly handle undefined properties").
• yarn test runs successfully