DOC: Added sjoin_nearest method to examples gallery. (#2259)

doc/source/gallery/spatial_joins.ipynb

@@ -213,6 +213,24 @@
    "source": [
     "pointdf.sjoin(polydf, how=\"left\", predicate=\"within\")"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "We can also conduct a nearest neighbour join with `sjoin_nearest`."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "pointdf.sjoin_nearest(polydf, how=\"left\", distance_col=\"Distances\")\n",
+    "# Note the optional Distances column with computed distances between each point\n",
+    "# and the nearest polydf geometry."
+   ]
   }
  ],
  "metadata": {