display summary in landing page

Author: jeffjennings

index-spectroscopy.ipynb

@@ -7,6 +7,7 @@
    "source": [
     "# Tutorial Series on Spectroscopic Data Reduction Basics\n",
     "\n",
+    "## Summary\n",
     "This is a set of tutorials on working with spectroscopic data. We will walk through the derivation of a spectroscopic trace model and extraction using astropy tools, extraction of a calibration lamp spectrum using an existing trace and identification using the NIST line list database, how to fit a wavelength solution to a calibration spectrum, how to apply a trace and a wavelength solution to science data, and how to do basic analysis like line fitting.\n"
    ]
   }