Add new links card and feature flag system for incremental dev.

[Prospector]

Begins the process of an incremental re-design, rather than attempting an entire overhaul at once.

• Added new "Links" card for project pages
• Added a framework for adding "feature flags" so work on features can be implemented and merged while still disabled, allowing us to fix any related bugs before officially rolling out a feature or design change
• Added WIP work on "Compatibility" and "Details" cards for redesign, but these are disabled for now with feature flags.