Update open source license

README.md

@@ -1,5 +1,5 @@
 ---
-license: apache-2.0
+license: cc-by-sa-4.0
 task_categories:
 - question-answering
 - text-generation
@@ -16,4 +16,4 @@ The purpose of this dataset is to provide the opportunity to perform any trainin
 
 In case it may be useful for other purposes, I have also included the dataset in CSV format.
 
-The dataset contains all the Question-Answer pairs from Stack Overflow with Kubernetes tags. Specifically, in each Question-Answer pair, the Answer is the one with a positive and maximum score. Posts on Stack Overflow with negative scores have been excluded from the dataset.
+All data in this dataset were retrieved from the Stack Exchange network using the Stack Exchange Data explorer tool (https://github.com/StackExchange/StackExchange.DataExplorer). Specifically, the dataset contains all the Question-Answer pairs from Stack Overflow with Kubernetes tags. Specifically, in each Question-Answer pair, the Answer is the one with a positive and maximum score. Posts on Stack Overflow with negative scores have been excluded from the dataset.