minor typo fix (#219)

Author: andersy005

intermediate/01-high-level-computation-patterns.ipynb

@@ -928,7 +928,7 @@
     "For instance, grouping data by month (which have varying numbers of days) or the results of an image classification.\n",
     "The GroupBy functions are essentially a generalization of `coarsen`: \n",
     "\n",
-    "- `groupby`: divide data into distinct groups, e.g. climatologies, composites. Works best when the \"group indentifiers\" or \"labels\" are exact and can be determined using equality (`==`), e.g. characters or integers. Remember that floats are not exact values.\n",
+    "- `groupby`: divide data into distinct groups, e.g. climatologies, composites. Works best when the \"group identifiers\" or \"labels\" are exact and can be determined using equality (`==`), e.g. characters or integers. Remember that floats are not exact values.\n",
     "- `groupby_bins`: Use binning operations, e.g. histograms, to group your data.\n",
     "- `resample`: Specialized implementation of GroupBy specifically for time grouping (so far), allows you to change sampling frequency of dataset.\n",
     "\n",