update header.js

src/js/07-header.js

@@ -16,7 +16,9 @@
   download.addEventListener('click', function () {
     var pathname = window.location.pathname
     var path = pathname.split('/')
-    var filename = path[3] ? path[3] === 'swlab-docs' ? 'docs' : `docs-${path[3]}` : ''
+    var isInternal = path[4].includes('-s')
+    var filename = path[3] ? path[3] === 'swlab-docs'
+      ? 'docs' : isInternal ? `docs-${path[3]}-s` : `docs-${path[3]}` : ''
     var directory = path[3] && path[4] ? path[3] === 'swlab-docs' ? path[3] : path[4] : ''
     var link = document.createElement('a')