Add 3.1 video

Author: cooper-mj

res/lectures.json

@@ -38,7 +38,7 @@
         "date": "2020-01-22",
         "condensed": "https://drive.google.com/open?id=1Yj2ymdqGqtoD-sLJc4yiH5aRGxW5U9-a",
         "full": "https://drive.google.com/open?id=1T9E97rcG2Ka6bAFciZH9zs9RjsneNiAj",
-        "video": "#",
+        "video": "https://drive.google.com/open?id=1266CkQGrP37vZRdzASlMCcIUxdqubelu",
         "video_note": "#",
         "visible": true,
         "active": true