added overleaf template to week39 draft

Author: KarlHenrik

doc/LectureNotes/exercisesweek39.ipynb

@@ -58,7 +58,7 @@
     "\n",
     "**a)** Create an account on Overleaf.com\n",
     "\n",
-    "**b)** Download [this]() template project.\n",
+    "**b)** Download [this](https://github.com/CompPhysics/MachineLearning/blob/master/doc/LectureNotes/data/FYS_STK_Template.zip) template project.\n",
     "\n",
     "**c)** Create a new Overleaf project with the correct formatting by uploading the template project.\n",
     "\n",