Added warning about quantization free service

Free services have limited quota and hence hard to hit the quantization threshold of 10000 documents unless the dimensions is very less. Hence quantization may never happen in SQ

Author: jasirkt

articles/search/vector-search-how-to-quantization.md

@@ -42,6 +42,8 @@ Two types of quantization are supported:
 
 - Binary quantization converts floats into binary bits, which takes up 1 bit. This results in up to 28 times reduced vector index size.
 
+**Note:** While free services support quantization, they may not demonstrate the full storage savings due to the limited storage quota.
+
 ## Add "compressions" to a search index
 
 The following example shows a partial index definition with a fields collection that includes a vector field, and a `vectorSearch.compressions` section.