Automatic merge of T1.5.1-799-gb02a6e5d3 and 16 pull requests

- Pull request #570 at 3539862: Experimental glTF 2.0 support with PBR lighting
- Pull request #839 at d00beb9: First phase of https://blueprints.launchpad.net/or/+spec/additional-cruise-control-parameters
- Pull request #876 at f92de76: docs: add source for documents previously on website to source Documentation folder
- Pull request #882 at b554363: Blueprint/train car operations UI window
- Pull request #885 at 8f94333: feat: Add notifications to Menu
- Pull request #886 at 6c0785b: Scene viewer extension to TrackViewer
- Pull request #892 at 1f5ba4c: Signal Function OPP_SIG_ID_TRAINPATH
- Pull request #896 at 5866028: First implementation of https://blueprints.launchpad.net/or/+spec/specific-sounds-for-ai-trains
- Pull request #897 at 42f1dd9: feat: Improved system information collection
- Pull request #899 at a0a37ac: Duplex steam engines - Booster Engine addition
- Pull request #903 at 0d6d045: Downloading route content (Github, zip)
- Pull request #907 at 9b0b04f: Bug fix for https://bugs.launchpad.net/or/+bug/2047300 Dynamic tracks disappear after long tunnel
- Pull request #908 at 4b4afe3: feat: supports switching adhesion precisions
- Pull request #911 at 6834af0: docs: Add refactoring as a special type of PR
- Pull request #912 at 9a12fbe: New Triple Valve Features Vol. 2
- Pull request #913 at 8286e27: chore: Add RTD configuration which is apparently required now

Author: openrails-bot

.readthedocs.yaml

@@ -0,0 +1,17 @@
+# Read the Docs configuration file for Sphinx projects
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+version: 2
+
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.12"
+
+sphinx:
+  configuration: Source/Documentation/Manual/conf.py
+
+formats:
+  - htmlzip
+  - pdf
+  - epub