Updated docs and dev requirements.

Author: insightindustry

docs/index.rst

@@ -30,7 +30,7 @@ Highcharts Maps for Python
 
 .. toctree::
   :hidden:
-  :maxdepth: 6
+  :maxdepth: 3
   :caption: Contents
 
   Home <self>

requirements.dev.txt

@@ -6,9 +6,9 @@ pytest-xdist==2.5.0
 python-dotenv==0.20.0
 pytz==2022.1
 Sphinx~=5.0.2
-sphinx-rtd-theme
-sphinx-toolbox>=3.2.0
-sphinx-tabs>=3.4.1
+sphinx-rtd-theme==0.5.1
+sphinx-toolbox==3.2.0
+sphinx-tabs==3.4.1
 requests==2.28.1
 urllib3==1.26.9
 validator-collection==1.5.0