Added credit for merge by array example

pkg/yqlib/doc/multiply-merge.md

@@ -239,6 +239,8 @@ so that there are no duplicates. The second half converts that map back to an ar
 
 To use this, you will need to update '.[]' to be the expression to your array (e.g. .my.array[]), and '.a' to be the key field of your array (e.g. '.name')
 
+Thanks Kev from [stackoverflow](https://stackoverflow.com/a/70109529/1168223)
+
 
 Given a sample.yml file of:
 ```yaml

pkg/yqlib/operator_multiply_test.go

@@ -33,6 +33,8 @@ var mergeArraysObjectKeysText = `There are two parts of the complex expression.
 so that there are no duplicates. The second half converts that map back to an array.
 
 To use this, you will need to update '.[]' to be the expression to your array (e.g. .my.array[]), and '.a' to be the key field of your array (e.g. '.name')
+
+Thanks Kev from [stackoverflow](https://stackoverflow.com/a/70109529/1168223)
 `
 
 var mergeExpression = `((.[] | {.a: .}) as $item ireduce ({}; . * $item )) as $uniqueMap