Display schematics images bundled with sketch in IDE

With Arduino IDE, we're always dealing with both software and hardware. However, a project usually contains nothing about the hardware part or some text description or a link to some dedicated description at best. This is somewhat hindering for both large projects and exmaples for beginners. Actually, I'm proposing this with an MVP for beginners in mind.

The idea is simple: once a beginner opens an exmaple from the list, if they see a curcuit picture on the right from the text area, it becomes much more clear what to do. Of'course, a full-blown editor like the one in TinkerCAD would be great, but that's a lot of efforts, while just a picture may still help very much. Adding such a picture may be the same as adding a tab, although displaying in a tab would be worse than displaying in a right sidebar/separate window.

For MVP, we may limit file format to JPEG (if that matters in terms of development simplicity) and require that is as a file is inside the project folder when we add it (although pasting from clipboard would ease the workflow much, especially if updated frequently).

No files, tests, or entry points are identified in the issue, so begin by locating the Arduino IDE example-opening and editor layout code. Done would require a defined MVP that loads a JPEG bundled in an example project and displays it beside the text area.

Written by the indexing model from the issue text.