Fix ReadTheDocs build

- Docs build now requires package installed
- Update tox docs to use Python 3.11, same as RTD

Author: medmunds

.readthedocs.yml

@@ -18,4 +18,6 @@ formats: all
 
 python:
   install:
+    - path: .
+      method: pip
     - requirements: docs/requirements.txt

tox.ini

@@ -102,7 +102,7 @@ commands =
     pre-commit run --all-files
 
 [testenv:docs]
-basepython = python3.10
+basepython = python3.11
 passenv =
     CONTINUOUS_INTEGRATION
 	# (but not any of the live test API keys)