docs(showcase): add "Model Context Protocol Specification"

Author: imfing

exampleSite/content/showcase/index.md

@@ -12,6 +12,13 @@ Open source projects powered by Hextra
 </p>
 
 {{< cards >}}
+  {{< card
+        link="https://github.com/modelcontextprotocol/specification"
+        title="Model Context Protocol Specification"
+        image="https://github.com/user-attachments/assets/1bb4f952-b8fc-43b5-9cbd-cd7213c2ba90"
+        imageStyle="object-fit:cover; aspect-ratio:16/9;"
+  >}}
+
   {{< card
         link="https://github.com/jonaspleyer/cellular_raza"
         title="cellular_raza"
@@ -84,7 +91,7 @@ Open source projects powered by Hextra
         link="https://hoa.moe/"
         title="HITSZ OpenAuto"
         image="https://raw.githubusercontent.com/HITSZ-OpenAuto/hoa.moe/main/static/images/showcase-new.png"
-        imageStyle="object-fit:cover; aspect-ratio:16/9;" 
+        imageStyle="object-fit:cover; aspect-ratio:16/9;"
   >}}
 
   {{< card