doc: use mkdocs [docs].

Author: jajupmochi

.actrc

@@ -0,0 +1,3 @@
+# .actrc
+# This file is used by the `act` tool to define the Docker image to use for the GitHub Actions (local) runner.
+-P ubuntu-latest=catthehacker/ubuntu:act-22.04

.github/workflows/docs.yml

@@ -0,0 +1,57 @@
+# .github/workflows/docs.yml
+name: Build and Deploy Documentation
+
+on:
+  push:
+    branches:
+      - main
+      - "v*.*.*"       # version branches like v1.0.1
+    tags-ignore:
+      - "**"
+    paths-ignore:
+      - "README.md"
+  workflow_dispatch:
+  # Optional: force build if commit message contains [docs]
+  workflow_call:
+
+jobs:
+  build-docs:
+    if: >
+      contains(github.event.head_commit.message, '[docs]') ||
+      (github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/heads/v'))
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout source
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install uv package manager
+        run: |
+          curl -LsSf https://astral.sh/uv/install.sh | sh
+          echo "~/.cargo/bin" >> $GITHUB_PATH
+
+      - name: Install documentation dependencies
+        run: |
+          uv pip install --system -r requirements-docs.txt
+
+      - name: Build documentation
+        run: |
+          mkdocs build --strict
+
+      - name: Upload built site as artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: site
+          path: site/
+
+      # Optional: deploy to GitHub Pages
+      # - name: Deploy to GitHub Pages
+      #   uses: peaceiris/actions-gh-pages@v4
+      #   with:
+      #     github_token: ${{ secrets.GITHUB_TOKEN }}
+      #     publish_dir: ./site

docs/Makefile renamed to docs_sphinx/Makefile

@@ -1,35 +1,35 @@
-@ECHO OFF
-
-pushd %~dp0
-
-REM Command file for Sphinx documentation
-
-if "%SPHINXBUILD%" == "" (
-	set SPHINXBUILD=sphinx-build
-)
-set SOURCEDIR=source
-set BUILDDIR=build
-
-if "%1" == "" goto help
-
-%SPHINXBUILD% >NUL 2>NUL
-if errorlevel 9009 (
-	echo.
-	echo.The 'sphinx-build' command was not found. Make sure you have Sphinx
-	echo.installed, then set the SPHINXBUILD environment variable to point
-	echo.to the full path of the 'sphinx-build' executable. Alternatively you
-	echo.may add the Sphinx directory to PATH.
-	echo.
-	echo.If you don't have Sphinx installed, grab it from
-	echo.http://sphinx-doc.org/
-	exit /b 1
-)
-
-%SPHINXBUILD% -M %1 %SOURCEDIR% %BUILDDIR% %SPHINXOPTS%
-goto end
-
-:help
-%SPHINXBUILD% -M help %SOURCEDIR% %BUILDDIR% %SPHINXOPTS%
-
-:end
-popd
+@ECHO OFF
+
+pushd %~dp0
+
+REM Command file for Sphinx documentation
+
+if "%SPHINXBUILD%" == "" (
+	set SPHINXBUILD=sphinx-build
+)
+set SOURCEDIR=source
+set BUILDDIR=build
+
+if "%1" == "" goto help
+
+%SPHINXBUILD% >NUL 2>NUL
+if errorlevel 9009 (
+	echo.
+	echo.The 'sphinx-build' command was not found. Make sure you have Sphinx
+	echo.installed, then set the SPHINXBUILD environment variable to point
+	echo.to the full path of the 'sphinx-build' executable. Alternatively you
+	echo.may add the Sphinx directory to PATH.
+	echo.
+	echo.If you don't have Sphinx installed, grab it from
+	echo.http://sphinx-doc.org/
+	exit /b 1
+)
+
+%SPHINXBUILD% -M %1 %SOURCEDIR% %BUILDDIR% %SPHINXOPTS%
+goto end
+
+:help
+%SPHINXBUILD% -M help %SOURCEDIR% %BUILDDIR% %SPHINXOPTS%
+
+:end
+popd