Pin Read the Docs Sphinx theme version for documentation

diff --git a/docs/requirements.txt b/docs/requirements.txt
index f5b13cd3a44184a7ffeee7cfd8c192ff7c6ce25e..4ad08f24b6e7f45f5d6e35545644be9ad8b89027 100644 (file)
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,3 +1,4 @@
 recommonmark==0.7.1
 sphinx==4.0.1
+sphinx_rtd_theme==0.5.2
 sphinxcontrib-trio==1.1.2