fix readthedocs build

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
new file mode 100644
index 0000000..12e88e9
--- /dev/null
+++ b/.readthedocs.yaml
@@ -0,0 +1,5 @@
+version: 2
+
+python:
+   install:
+   - requirements: requirements.txt
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..93120e6
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+docutils<0.18