Add three new notebooks to TOC

Author: rcpeene

docs/_toc.yml

@@ -13,3 +13,6 @@ parts:
   - file: visualization/visualize_2p_raw.ipynb
   - file: visualization/visualize_neuropixel_probes.ipynb
   - file: visualization/visualize_lfp_responses.ipynb
+  - file: visualization/visualize_unit_metrics.ipynb
+  - file: visualization/visualize_unit_responses.ipynb
+  - file: visualization/visualize_2p_responses.ipynb