Add a newline before the last quotation mark in copy curl

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

assets/js/copy-button.js

@@ -62,7 +62,7 @@ function addCurl(textToCopy) {
     result += path + "\"";
 
     if (body.length > 0) {
-        result += " -H 'Content-Type: application/json' -d'\n" + body + "'";
+        result += " -H 'Content-Type: application/json' -d'\n" + body + "\n'";
     }
 
     return result;