config: add .readthedocs.yaml

Add a .readthedocs.yaml configuration file.

Signed-off-by: Joakim Bech <joakim.bech@linaro.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

.readthedocs.yaml

@@ -0,0 +1,11 @@
+version: 2
+
+# Build from the docs/ directory with Sphinx
+sphinx:
+  configuration: conf.py
+
+# Explicitly set the version of Python and its requirements
+python:
+  version: 3.7
+  install:
+    - requirements: requirements.txt