docs: update documentation

Author: hashemix

docs/_media/mcp-discovery-xpost.png

@@ -17,14 +17,14 @@
   <meta property="og:type" content="website">
   <meta property="og:site_name" content="MCP Discovery">
 
-  <meta property="og:image" content="https://rust-mcp-stack.github.io/mcp-discovery/_media/mcp-discovery.png">
+  <meta property="og:image" content="https://rust-mcp-stack.github.io/mcp-discovery/_media/mcp-discovery-xpost.png">
   <meta property="og:image:alt" content="MCP Discovery logo">
 
 
   <meta name="twitter:card" content="summary_large_image">
   <meta name="twitter:title" content="MCP Discovery: A Rust-based CLI tool for discovering MCP Server capabilities.">
   <meta name="twitter:description" content="MCP Discovery: A Rust-based CLI tool for discovering and documenting MCP Server capabilities in multiple formats.">
-  <meta name="twitter:image" content="https://rust-mcp-stack.github.io/mcp-discovery/_media/mcp-discovery.png">
+  <meta name="twitter:image" content="https://rust-mcp-stack.github.io/mcp-discovery/_media/mcp-discovery-xpost.png">
   <meta name="twitter:image:alt" content="MCP Discovery">
   <meta name="twitter:site" content="@rustmcp">