docs: move .readthedocs.yaml to the root of repo

Change-Id: I6c5afb806c47c029359a2dee2a7e73c6d076cfb1

runtime/.readthedocs.yaml

@@ -1,18 +0,0 @@
-# Read the Docs configuration file
-# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
-
-version: 2
-
-sphinx:
-   configuration: runtime/docs/conf.py
-
-formats: [htmlzip, pdf, epub]
-
-python:
-   install:
-   - requirements: runtime/docs/sphinx/requirements.txt
-
-build:
-   os: ubuntu-22.04
-   tools:
-      python: "3.10"