first-light-og — social share-card image Worker

GET /og/card.png              generic branded card
GET /og/network.png           live state-of-the-chain card
GET /og/block?h=<hash|height> per-block card
GET /og/miners.png            miner world-map counts card
GET /og/ig?type=<t>&...       1080x1080 square (Instagram); t=card|network|block|miners