Implement locally stored docs. Uses web when local not available.

docs/build-docs.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python3
+
+import os
+import shutil
+import subprocess
+import sys
+
+
+def main():
+    if len(sys.argv) != 4:
+        raise SystemExit("usage: build-docs.py SOURCE_DIR OUTPUT_DIR STAMP_FILE")
+
+    source_dir = os.path.abspath(sys.argv[1])
+    output_dir = os.path.abspath(sys.argv[2])
+    stamp_file = os.path.abspath(sys.argv[3])
+    doctree_dir = output_dir + ".doctrees"
+
+    shutil.rmtree(output_dir, ignore_errors=True)
+    shutil.rmtree(doctree_dir, ignore_errors=True)
+    os.makedirs(output_dir, exist_ok=True)
+
+    subprocess.run(
+        [
+            sys.executable,
+            "-m",
+            "sphinx",
+            "-b",
+            "html",
+            "-d",
+            doctree_dir,
+            source_dir,
+            output_dir,
+        ],
+        check=True,
+    )
+
+    with open(stamp_file, "w", encoding="utf-8") as stamp:
+        stamp.write("built\n")
+
+
+if __name__ == "__main__":
+    main()