fix title (#67)

Author: e-marshall

book/itslive/nbs/5_exploratory_data_analysis_group.ipynb

@@ -5,7 +5,7 @@
    "id": "4e79c758-1b29-4abd-b288-735f379d0284",
    "metadata": {},
    "source": [
-    "# 4.5 Comparing Sentinel-1 RTC datasets\n",
+    "# 3.5 Exploratory data analysis of multiple glaciers\n",
     "\n",
     "## Introduction\n",
     "\n",