[DOCS] EQL: Remove multi-value field limitation (#76663)

Changes:
* Removes the limitation for multi-value fields.
* Adds a recommendation to avoid complex expressions for Boolean comparisons to the `string` fn.

Relates to #76610.

docs/reference/eql/syntax.asciidoc

@@ -819,14 +819,6 @@ EQL searches do not support <<text,`text`>> fields. To a search a `text` field,
 use the EQL search API's <<eql-search-filter-query-dsl,Query DSL `filter`>>
 parameter.
 
-[discrete]
-[[eql-array-fields]]
-==== Array field values are not supported
-
-EQL does not support <<array,array>> field values, also known as
-multi-value fields. EQL searches on array field values may return inconsistent
-results.
-
 [discrete]
 [[eql-nested-fields]]
 ==== EQL search on nested fields