docs(#373): verify sortBy already implemented for VectorQuery and VectorRangeQuery

Issue #373 requested adding sortBy support to VectorQuery and
VectorRangeQuery. Investigation reveals this feature is already fully
implemented:

Implementation:
- VectorQuery: sortBy() and sortDescending() methods (lines 817-831)
- VectorRangeQuery: sortBy() and sortDescending() methods (lines 367-381)
- SearchIndex.searchWithSort() applies sorting via Jedis (lines 1360-1399)
- Sorting parameters properly passed through query execution pipeline

Test Coverage:
- QuerySortingIntegrationTest with 4 passing tests
- testSortVectorQuery: ascending sort verification
- testSortVectorQueryDescending: descending sort verification
- testSortVectorRangeQuery: range query sorting
- testSortFilterQueryAlreadyWorks: baseline comparison

Changes:
- Removed outdated test comments claiming methods don't exist
- No implementation changes needed

Tests: 282 passed, 14 skipped (API keys)

Closes #373 - feature already complete with full test coverage

Author: bsbodden

core/src/test/java/com/redis/vl/query/QuerySortingIntegrationTest.java

@@ -179,7 +179,7 @@ void testSortVectorQuery() {
             .field("user_embedding")
             .vector(new float[] {0.1f, 0.1f, 0.5f})
             .returnFields(List.of("user", "credit_score", "age", "job", "location", "last_updated"))
-            .sortBy("age") // THIS WILL FAIL - sortBy doesn't exist yet!
+            .sortBy("age")
             .build();
 
     List<Map<String, Object>> results = index.query(query);
@@ -244,7 +244,7 @@ void testSortVectorQueryDescending() {
             .vector(new float[] {0.1f, 0.1f, 0.5f})
             .returnFields(List.of("user", "age"))
             .sortBy("age")
-            .sortDescending(true) // THIS WILL FAIL - sortDescending doesn't exist yet!
+            .sortDescending(true)
             .build();
 
     List<Map<String, Object>> results = index.query(query);