ReadTheDocs now requires additional configuration

Provide required configuration file `.readthedocs.yaml` and follow
ReadTheDocs best practice to create reproducable builds.

https://docs.readthedocs.io/en/stable/guides/reproducible-builds.html

Signed-off-by: Stephen Tiedemann <stephen.tiedemann@gmail.com>

.readthedocs.yaml

@@ -0,0 +1,13 @@
+version: 2
+
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.11"
+
+sphinx:
+  configuration: docs/conf.py
+
+python:
+  install:
+    - requirements: docs/requirements.txt

MANIFEST.in

@@ -5,4 +5,5 @@ recursive-include docs *.ico
 recursive-include docs *.png
 recursive-include docs *.py
 recursive-include docs *.rst
+recursive-include docs *.txt
 prune docs/_build

docs/requirements.in

@@ -0,0 +1,7 @@
+#
+# Required packages for build on readthedocs.org
+#
+sphinx==7.2.5
+sphinx_rtd_theme==1.3.0
+readthedocs-sphinx-search==0.3.1
+sphinxcontrib-programoutput==0.17

docs/requirements.txt

@@ -0,0 +1,67 @@
+#
+# This file is autogenerated by pip-compile with Python 3.11
+# by the following command:
+#
+#    pip-compile docs/requirements.in
+#
+alabaster==0.7.13
+    # via sphinx
+babel==2.12.1
+    # via sphinx
+certifi==2023.7.22
+    # via requests
+charset-normalizer==3.2.0
+    # via requests
+docutils==0.18.1
+    # via
+    #   sphinx
+    #   sphinx-rtd-theme
+idna==3.4
+    # via requests
+imagesize==1.4.1
+    # via sphinx
+jinja2==3.1.2
+    # via sphinx
+markupsafe==2.1.3
+    # via jinja2
+packaging==23.1
+    # via sphinx
+pygments==2.16.1
+    # via sphinx
+readthedocs-sphinx-search==0.3.1
+    # via -r docs/requirements.in
+requests==2.31.0
+    # via sphinx
+snowballstemmer==2.2.0
+    # via sphinx
+sphinx==7.2.5
+    # via
+    #   -r docs/requirements.in
+    #   sphinx-rtd-theme
+    #   sphinxcontrib-applehelp
+    #   sphinxcontrib-devhelp
+    #   sphinxcontrib-htmlhelp
+    #   sphinxcontrib-jquery
+    #   sphinxcontrib-programoutput
+    #   sphinxcontrib-qthelp
+    #   sphinxcontrib-serializinghtml
+sphinx-rtd-theme==1.3.0
+    # via -r docs/requirements.in
+sphinxcontrib-applehelp==1.0.7
+    # via sphinx
+sphinxcontrib-devhelp==1.0.5
+    # via sphinx
+sphinxcontrib-htmlhelp==2.0.4
+    # via sphinx
+sphinxcontrib-jquery==4.1
+    # via sphinx-rtd-theme
+sphinxcontrib-jsmath==1.0.1
+    # via sphinx
+sphinxcontrib-programoutput==0.17
+    # via -r docs/requirements.in
+sphinxcontrib-qthelp==1.0.6
+    # via sphinx
+sphinxcontrib-serializinghtml==1.1.9
+    # via sphinx
+urllib3==2.0.4
+    # via requests

tox.ini

@@ -17,8 +17,7 @@ commands = flake8 src tests setup.py
 setenv =
     PYTHONHASHSEED = 313
 deps =
-    sphinx
-    sphinxcontrib-programoutput
+    -r docs/requirements.txt
 commands =
     sphinx-build -W -b html -d {envtmpdir}/doctrees docs docs/_build/html
     sphinx-build -W -b doctest -d {envtmpdir}/doctrees docs docs/_build/html