Change title and thumbnail, fix spelling errors

docs/notebooks/count_roaches.ipynb

@@ -29,7 +29,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Poisson and Negative Binomial regression example with offsets\n",
+    "# Count Regression with Variable Exposure\n",
     "\n",
     "This example is based on the [\"Roaches\"](https://github.com/avehtari/ROS-Examples/tree/master/Roaches/) example from [Regression and Other Stories](https://avehtari.github.io/ROS-Examples/index.html) by Gelman, Hill, and Vehtari.   The example is a count regression model with an offset term. \n",
     "\n",
@@ -420,7 +420,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "It appears that we are drastically underpredicing the number of appartments with a small number of roaches.  This suggests creating a test statistic measuring the fraction of zeros, both in the observed data and in the simulated replications (posterior predictions).  We can then use this to check the model fit."
+    "It appears that we are drastically under predicting the number of apartments with a small number of roaches.  This suggests creating a test statistic measuring the fraction of zeros, both in the observed data and in the simulated replications (posterior predictions).  We can then use this to check the model fit."
    ]
   },
   {

docs/notebooks/gallery.yml

@@ -72,7 +72,7 @@
       subtitle: Students absence
       href: negative_binomial.ipynb
       thumbnail: thumbnails/negative_binomial.png
-    - title: Count Data with Offsets
+    - title: Count Regression with Variable Exposure
       subtitle: Accounting for varying exposure using offsets
       href: count_roaches.ipynb
       thumbnail: thumbnails/roaches.png