feat: update projects page description

- Replace generic description with research-focused introduction
- Highlight focus on audio LLMs, speech understanding, and intelligent interaction

Author: FlyTia

content/projects/_index.md

@@ -12,7 +12,7 @@ sections:
   - block: collection
     content:
       title: Selected Projects
-      text: I enjoy making things. Here are a selection of projects that I have worked on over the years.
+      text: Pioneering work in end-to-end audio large language models, focusing on speech understanding, generation, and intelligent interaction systems.
       filters:
         folders:
           - projects