feat: update whitepaper roadmap image

Author: yongenaelf

docs/resources/whitepaper-2/roadmap/index.md

@@ -3,7 +3,7 @@ sidebar_position: 10
 title: "aelf 2025 Roadmap: AI Blockchain Developments"
 description: aelf's 2025 roadmap sees updates on modular blockchain architecture, AI integration, and enhanced scalability. Shared by aelf, AI blockchain.
 ---
-![aelf Roadmap](/img/aelf_roadmap_2.png "aelf Roadmap")
+![aelf Roadmap](roadmap.png)
 
 # aelf 2025 Roadmap: Introduction