add document generation to tox, and trigger automatically at CI (also check links in documentation to avoid having dangling pointers to the internet)
diff --git a/docs/conf.py b/docs/conf.py
index 95695ab..79b71f8 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -135,7 +135,7 @@
# Add any paths that contain custom static files (such as style sheets) here,
# relative to this directory. They are copied after the builtin static files,
# so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['_static']
+html_static_path = []
# Add any extra paths that contain custom files (such as robots.txt or
# .htaccess) here, relative to this directory. These files are copied