need to install ourself, for readthedocs

.readthedocs.yaml

@@ -30,6 +30,7 @@ sphinx:
 # Optional but recommended, declare the Python requirements required
 # to build your documentation
 # See https://docs.readthedocs.io/en/stable/guides/reproducible-builds.html
-# python:
-#   install:
-#     - requirements: docs/requirements.txt
+python:
+   install:
+     - method: pip
+       path: .