Remove NSIDC logo from intro notebook

Top-level website displays logo

Author: trey-stafford

docs/notebooks/0_introduction.ipynb

@@ -5,7 +5,6 @@
    "metadata": {},
    "source": [
     "<center>\n",
-    "<img src='./img/nsidc_logo.png'/>\n",
     "\n",
     "# Altimetry Data at the NSIDC DAAC\n",
     "#### Point Cloud Data Overview\n",