adds support for Read the Docs

This lets new_cxx_project's documentation be hosted in a HTML format.

Issue #5

.readthedocs.yml

@@ -0,0 +1,20 @@
+# .readthedocs.yaml
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+# Required
+version: 2
+
+# Set the OS, Python version and other tools you might need
+build:
+  os: ubuntu-24.04
+  tools:
+    python: "3.12"
+
+# Build documentation in the "docs/" directory with Sphinx
+sphinx:
+  configuration: docs/conf.py
+
+python:
+   install:
+   - requirements: docs/requirements.txt

docs/requirements.in

@@ -0,0 +1,3 @@
+sphinx
+myst-parser
+psutil

docs/requirements.txt

@@ -0,0 +1,68 @@
+#
+# This file is autogenerated by pip-compile with Python 3.12
+# by the following command:
+#
+#    pip-compile requirements.in
+#
+alabaster==0.7.16
+    # via sphinx
+babel==2.15.0
+    # via sphinx
+certifi==2024.7.4
+    # via requests
+charset-normalizer==3.3.2
+    # via requests
+docutils==0.21.2
+    # via
+    #   myst-parser
+    #   sphinx
+idna==3.7
+    # via requests
+imagesize==1.4.1
+    # via sphinx
+jinja2==3.1.4
+    # via
+    #   myst-parser
+    #   sphinx
+markdown-it-py==3.0.0
+    # via
+    #   mdit-py-plugins
+    #   myst-parser
+markupsafe==2.1.5
+    # via jinja2
+mdit-py-plugins==0.4.1
+    # via myst-parser
+mdurl==0.1.2
+    # via markdown-it-py
+myst-parser==3.0.1
+    # via -r requirements.in
+packaging==24.1
+    # via sphinx
+psutil==6.0.0
+    # via -r requirements.in
+pygments==2.18.0
+    # via sphinx
+pyyaml==6.0.1
+    # via myst-parser
+requests==2.32.3
+    # via sphinx
+snowballstemmer==2.2.0
+    # via sphinx
+sphinx==7.4.7
+    # via
+    #   -r requirements.in
+    #   myst-parser
+sphinxcontrib-applehelp==2.0.0
+    # via sphinx
+sphinxcontrib-devhelp==2.0.0
+    # via sphinx
+sphinxcontrib-htmlhelp==2.1.0
+    # via sphinx
+sphinxcontrib-jsmath==1.0.1
+    # via sphinx
+sphinxcontrib-qthelp==2.0.0
+    # via sphinx
+sphinxcontrib-serializinghtml==2.0.0
+    # via sphinx
+urllib3==2.2.2
+    # via requests