Fix type-checking errors in snippets (code only, no .md)

This commit both:
- Fixes pre-existing mistakes in snippets, aka wrong code samples.
- Adds hidden (`@hide`) statements that do not appear in the docs,
  but satisfy typecheckers.

qdrant-landing/content/documentation/headless/snippets/create-collection/with-vectors-on-disk/go.go

@@ -12,6 +12,8 @@ func Main() {
 		Port: 6334,
 	})
 
+	if err != nil { panic(err) } // @hide
+
 	client.CreateCollection(context.Background(), &qdrant.CreateCollection{
 		CollectionName: "{collection_name}",
 		VectorsConfig: qdrant.NewVectorsConfig(&qdrant.VectorParams{