Remove unsupported xAI and DeepSeek code examples from documentation (#140)

Author: chrisraygill

src/content/docs/index.mdx

@@ -256,61 +256,6 @@ func main() {
 	log.Println(resp.Text())
 }
 
-````
-</TabItem>
-<TabItem label="xAI">
-```go
-import (
-	"context"
-	"log"
-
-	"github.com/firebase/genkit/go/ai"
-	"github.com/firebase/genkit/go/genkit"
-	"github.com/firebase/genkit/go/plugins/compat_oai/xai"
-)
-
-func main() {
-	ctx := context.Background()
-	g := genkit.Init(ctx, genkit.WithPlugins(&xai.XAI{}))
-
-	resp, err := genkit.Generate(ctx, g,
-		ai.WithPrompt("Why is Firebase awesome?"),
-		ai.WithModelName("xai/grok-3-mini"),
-	)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	log.Println(resp.Text())
-}
-````
-</TabItem>
-<TabItem label="DeepSeek">
-```go
-import (
-	"context"
-	"log"
-
-	"github.com/firebase/genkit/go/ai"
-	"github.com/firebase/genkit/go/genkit"
-	"github.com/firebase/genkit/go/plugins/compat_oai/deepseek"
-)
-
-func main() {
-	ctx := context.Background()
-	g := genkit.Init(ctx, genkit.WithPlugins(&deepseek.DeepSeek{}))
-
-	resp, err := genkit.Generate(ctx, g,
-		ai.WithPrompt("Why is Firebase awesome?"),
-		ai.WithModelName("deepseek/deepseek-chat"),
-	)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	log.Println(resp.Text())
-}
-
 ````
 </TabItem>
 <TabItem label="Ollama">