docs: enhance MCP servers documentation with a tip (#6713)

packages/web/src/content/docs/mcp-servers.mdx

@@ -23,7 +23,7 @@ Certain MCP servers, like the GitHub MCP server, tend to add a lot of tokens and
 
 ## Enable
 
-You can define MCP servers in your OpenCode config under `mcp`. Add each MCP with a unique name. You can refer to that MCP by name when prompting the LLM.
+You can define MCP servers in your [OpenCode Config](https://opencode.ai/docs/config/) under `mcp`. Add each MCP with a unique name. You can refer to that MCP by name when prompting the LLM.
 
 ```jsonc title="opencode.jsonc" {6}
 {