Fix Minimal example and ARIMA family heading (#694)

README.md

@@ -43,7 +43,9 @@ Vist our [Installation Guide](https://nixtla.github.io/statsforecast/docs/gettin
 ```python
 from statsforecast import StatsForecast
 from statsforecast.models import AutoARIMA
+from statsforecast.utils import AirPassengersDF
 
+df = AirPassengersDF
 sf = StatsForecast(
     models = [AutoARIMA(season_length = 12)],
     freq = 'M'
@@ -114,7 +116,7 @@ Automatic forecasting tools search for the best parameters and select the best p
 |[AutoCES](https://nixtla.github.io/statsforecast/src/core/models.html#autoces)|✅|✅|✅|✅|✅|
 |[AutoTheta](https://nixtla.github.io/statsforecast/src/core/models.html#autotheta)|✅|✅|✅|✅|✅|
 
-## ARIMA Family
+### ARIMA Family
 These models exploit the existing autocorrelations in the time series.
 
 |Model | Point Forecast | Probabilistic Forecast | Insample fitted values | Probabilistic fitted values |
@@ -259,4 +261,4 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
 
 <!-- ALL-CONTRIBUTORS-LIST:END -->
 
-This project follows the [all-contributors](https://github.com/all-contributors/all-contributors) specification. Contributions of any kind welcome!
+This project follows the [all-contributors](https://github.com/all-contributors/all-contributors) specification. Contributions of any kind welcome!

nbs/index.ipynb

@@ -72,7 +72,9 @@
     "```python\n",
     "from statsforecast import StatsForecast\n",
     "from statsforecast.models import AutoARIMA\n",
+    "from statsforecast.utils import AirPassengersDF\n",
     "\n",
+    "df = AirPassengersDF\n",
     "sf = StatsForecast(\n",
     "    models = [AutoARIMA(season_length = 12)],\n",
     "    freq = 'M'\n",
@@ -176,7 +178,7 @@
     "|[AutoTheta](https://nixtla.github.io/statsforecast/src/core/models.html#autotheta)|✅|✅|✅|✅|✅|\n",
     ": {tbl-colwidths=\"[75,25]\"}\n",
     "\n",
-    "## ARIMA Family\n",
+    "### ARIMA Family\n",
     "These models exploit the existing autocorrelations in the time series.\n",
     "\n",
     "|Model | Point Forecast | Probabilistic Forecast | Insample fitted values | Probabilistic fitted values |\n",