NRL-518 Update postman link in documentation

Author: axelkrastek1-nhs

swagger/consumer-static/narrative.yaml

@@ -190,7 +190,7 @@ info:
 
     Right click the icon and save link as... to save the Postman collection to your device
 
-    [![Right click and save link as...](https://run.pstmn.io/button.svg)](https://github.com/NHSDigital/NRLF/raw/main/postman_collection.json)
+    [![Right click and save link as...](https://run.pstmn.io/button.svg)](https://github.com/NHSDigital/NRLF/raw/develop/postman_collection.json)
 
     ### Integration testing
 

swagger/producer-static/narrative.yaml

@@ -179,7 +179,7 @@ info:
 
     Right click the icon and save link as... to save the Postman collection to your device
 
-    [![Right click and save link as...](https://run.pstmn.io/button.svg)](https://github.com/NHSDigital/NRLF/raw/main/postman_collection.json)
+    [![Right click and save link as...](https://run.pstmn.io/button.svg)](https://github.com/NHSDigital/NRLF/raw/develop/postman_collection.json)
 
     ### Integration testing