Add ability to expand images in major project listing

Images are displayed in the collapsible content for major projects, but they are pretty small, so can be very difficult to read stuff in images. It would be good if it was possible to click on an image to expand it

No file or test is named in the issue. Start by locating the major project listing and its collapsible image markup, then verify that clicking an image opens an enlarged, readable view while preserving the existing listing behavior.

Written by the indexing model from the issue text.