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/insert-points/with-multivector/go.go

@@ -12,6 +12,8 @@ func Main() {
 		Port: 6334,
 	})
 
+	if err != nil { panic(err) } // @hide
+
 	client.Upsert(context.Background(), &qdrant.UpsertPoints{
 		CollectionName: "{collection_name}",
 		Points: []*qdrant.PointStruct{

qdrant-landing/content/documentation/headless/snippets/insert-points/with-multivector/rust.rs

@@ -1,5 +1,5 @@
 use qdrant_client::qdrant::{PointStruct, UpsertPointsBuilder, Vector};
-use qdrant_client::Qdrant;
+use qdrant_client::{Payload, Qdrant};
 
 pub async fn main() -> anyhow::Result<()> {
     let client = Qdrant::from_url("http://localhost:6334").build()?;

qdrant-landing/content/documentation/headless/snippets/insert-points/with-multivector/typescript.ts

@@ -7,9 +7,9 @@ client.upsert("{collection_name}", {
     {
       id: 1,
       vector: [
-        [-0.013,  0.020, -0.007, -0.111, ...],
-        [-0.030, -0.055,  0.001,  0.072, ...],
-        [-0.041,  0.014, -0.032, -0.062, ...]
+        [-0.013,  0.020, -0.007, -0.111],
+        [-0.030, -0.055,  0.001,  0.072],
+        [-0.041,  0.014, -0.032, -0.062]
       ],
     }
   ]