commit 835bb2be9e00c50e5751d271380ac00fe98f8d07
Author: Karolina Surma <33810531+befeleme@users.noreply.github.com>
Date:   Tue Jun 15 18:47:42 2021

    Replace call to add_stylesheet with add_css_file
    
    This should prevent documentation build failures with Sphinx 4.

diff --git a/docs/source/conf.py b/docs/source/conf.py
index c3f6e2f..ab160e1 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -38,7 +38,7 @@ extensions = [
 ]
 
 def setup(app):
-    app.add_stylesheet("hack.css")
+    app.add_css_file("hack.css")
 
 intersphinx_mapping = {
     "sphinx": ("http://www.sphinx-doc.org/en/stable/", None),