External repo links on About page open in same tab with no rel attribute

[presidojay1]

The "Open source, top to bottom" links point to https://github.com/... but lack target="_blank" and rel="noopener noreferrer", so clicking one navigates the user away from the app entirely instead of opening the repo in a new tab.

Suggested fix: Add target="_blank" rel="noopener noreferrer" to each of the three anchor tags.