Add todo list items to Quantities tutorial

Author: kakirastern

tutorials/notebooks/quantities/quantities.ipynb

@@ -7,7 +7,7 @@
     "# Using Astropy Quantities for astrophysical calculations\n",
     "\n",
     "## Authors\n",
-    "Ana Bonaca, Erik Tollerud, Jonathan Foster\n",
+    "Ana Bonaca, Erik Tollerud, Jonathan Foster, Kris Stern\n",
     "\n",
     "## Learning Goals\n",
     "* Learn how to instantiate `astropy.units.Quantity` objects\n",
@@ -20,6 +20,9 @@
     "* Use the small angle approximation with `astropy.units.dimensionless_angles` equivalencies\n",
     "* Write functions with explicit units to prevent your Mars orbiter from crashing\n",
     "* Make synthetic radio observations\n",
+    "1. Use `Quantity` objects to estimate a hypothetical galaxy's mass\n",
+    "2. Use `Quantity` objects such as data cubes to facilitate a full derivation of the total mass of a molecular cloud\n",
+    "3. Write functions that take `Quantity` objects instead of raw numbers or arrays\n",
     "\n",
     "## Keywords\n",
     "units, matplotlib, radio astronomy, data cubes\n",
@@ -1516,5 +1519,5 @@
   }
  },
  "nbformat": 4,
- "nbformat_minor": 1
+ "nbformat_minor": 2
 }