update the contents page of examples to include ITS

Author: agroutsmith

docs/source/examples.rst

@@ -1,5 +1,5 @@
-Nonequivalent group designs
-===========================
+ANCOVA
+======
 
 .. toctree::
    :titlesonly:
@@ -15,10 +15,7 @@ Synthetic Control
 
    notebooks/sc_pymc.ipynb
    notebooks/sc_skl.ipynb
-   notebooks/sc2_pymc.ipynb
-   notebooks/sc2_skl.ipynb
    notebooks/sc_pymc_brexit.ipynb
-   notebooks/its_covid.ipynb
    notebooks/geolift1.ipynb
 
 
@@ -33,6 +30,17 @@ Difference in Differences
    notebooks/did_pymc_banks.ipynb
 
 
+Interrupted Time Series
+=======================
+
+.. toctree::
+   :titlesonly:
+
+   notebooks/sc2_pymc.ipynb
+   notebooks/sc2_skl.ipynb
+   notebooks/its_covid.ipynb
+
+
 Regression Discontinuity
 ========================