Fix code block formatting in sdk.mdx (#2312)

packages/web/src/content/docs/docs/sdk.mdx

@@ -50,7 +50,7 @@ const client = createOpencodeClient({
 
 You can also programmatically start an opencode server:
 
-````javascript
+```javascript
 import { createOpencodeServer } from "@opencode-ai/sdk"
 
 const server = await createOpencodeServer({
@@ -61,7 +61,7 @@ const server = await createOpencodeServer({
 console.log(`Server running at ${server.url}`)
 
 server.close()
-}
+```
 
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