null isn't exactly a valid value, rewording

modules/ROOT/pages/indexes/semantic-indexes/vector-indexes.adoc

@@ -132,14 +132,14 @@ OPTIONS { indexConfig: {
 The dimensionality of the vectors to be indexed, see xref:indexes/semantic-indexes/vector-indexes.adoc#embeddings[].
 Setting this value will ensure only vectors with the configured dimensionality will be indexed, and querying the index with a vector of a different dimensionality will return an error. It is recommended to provide the dimensions.
 Accepted values::: `INTEGER` between `1` and `4096` inclusively.
-Default Value::: `NULL`. Setting was mandatory prior to Neo4j 5.23.
+Default Value::: None, though the setting can be omitted. The setting was mandatory prior to Neo4j 5.23.
 
 `vector.similarity_function` ::
 The name of the similarity function to use to define how similar two vectors are.
 To read more about the available similarity functions, see xref:indexes/semantic-indexes/vector-indexes.adoc#similarity-functions[].
 
 Accepted values::: `STRING`: `'cosine'`, `'euclidean'`.
-Default Value::: `'cosine'`. Setting was mandatory prior to Neo4j 5.23.
+Default Value::: `'cosine'`. The setting was mandatory prior to Neo4j 5.23.
 
 `vector.quantization.enabled` label:new[Introduced in 5.23] ::
 Quantization is a technique to reduce the size of vector representations.