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-payload-index/lowercase-full-text/go.go

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

qdrant-landing/content/documentation/headless/snippets/create-payload-index/lowercase-full-text/python.py

@@ -6,7 +6,7 @@ client.create_payload_index(
     collection_name="{collection_name}",
     field_name="name_of_the_field_to_index",
     field_schema=models.TextIndexParams(
-        type="text",
+        type=models.TextIndexType.TEXT,
         tokenizer=models.TokenizerType.WORD,
         lowercase=False,
     ),