Add <style> to leios component diagram

Author: ch1bo

docs/leios-design/README.md

@@ -34,7 +34,7 @@ This document is a living artifact and will be updated as implementation progres
 
 # Architecture
 
-Ouroboros Leios is a significant change to the consensus protocol, but does not require fundamental changes to the overall architecture of the Cardano node. Several new components will be needed for the new responsibilities related to producing and relaying Endorser Blocks (EBs) and voting on them, as well as changes to existing components to support higher throughput and freshest-first-delivery. The following diagram illustrates the key components of a relay node where new and updated components are marked by small purple circles:
+Ouroboros Leios is a significant change to the consensus protocol, but does not require fundamental changes to the overall architecture of the Cardano node. Several new components will be needed for the new responsibilities related to producing and relaying Endorser Blocks (EBs) and voting on them, as well as changes to existing components to support higher throughput and freshest-first-delivery. The following diagram illustrates the key components of a relay node where new and updated components are marked in purple:
 
 ![](./relay-leios-component-diagram.svg)