refactor(docs): switch to nixos-render-docs for nix options generation

- Use nixos-render-docs commonmark as the rendering engine
- Add GitHub source links (Declared by) for each option
- Fix installation.md links pointing to /docs/nix-module -> /docs/nix-options

.github/scripts/generate-nix-options-docs.py

@@ -1,22 +1,9 @@
 #!/usr/bin/env python3
-"""
-Converts NixOS options JSON into clean Markdown documentation.
-"""
-
-import json
-import sys
+# Post-processes nixos-render-docs commonmark output into a single docs page.
+# Input: two pre-rendered .md files (NixOS and HM), produced by nixos-render-docs.
+# Steps: strip internal _module.args section, promote ## headings to ###.
 import re
-
-SECTIONS = [
-    {
-        "title": "NixOS",
-        "subtitle": "**System-level options via `programs.mango`.**",
-    },
-    {
-        "title": "Home Manager",
-        "subtitle": "**Configure mangowm declaratively via `wayland.windowManager.mango`.**",
-    },
-]
+import sys
 
 HEADER = (
     "---\n"
@@ -26,87 +13,36 @@ HEADER = (
     "> **Note:** This document is automatically generated from the Nix module source code.\n\n"
 )
 
-def clean_description(desc: str) -> str:
-    """Strips Nix inline markup tags, fixes dangling periods, and formats blockquotes."""
-    if not desc:
-        return "*No description provided.*"
+SECTIONS = [
+    ("NixOS", "**System-level options via `programs.mango`.**"),
+    ("Home Manager", "**Configure mangowm declaratively via `wayland.windowManager.mango`.**"),
+]
 
-    # Strip Nix inline markup: {tag}`content` → `content`; bare tags → ""
-    desc = re.sub(r'\{(?:var|option|manpage|file|env|command|program)\}(`[^`]+`)', r'\1', desc)
-    desc = re.sub(r'\{(?:var|option|manpage|file|env|command|program)\}', '', desc)
-    # Remove period left on its own line after tag removal
-    desc = re.sub(r'\n\s*\.(\s|$)', r'.\1', desc)
 
-    lines = desc.splitlines()
-    cleaned = []
-    in_block = False
+def process(md):
+    # Remove internal _module.args option injected by the module system
+    md = re.sub(r'## _module\\\.args.*?(?=\n## |\Z)', '', md, flags=re.DOTALL)
+    # Promote option headings (##) to subheadings (###) under the section (##)
+    md = re.sub(r'^## ', '### ', md, flags=re.MULTILINE)
+    return md.strip()
 
-    for line in lines:
-        m = re.match(r':::\s*\{\.(\w+)\}', line)
-        if m:
-            block_type = m.group(1).capitalize()
-            in_block = True
-            cleaned.append(f"> **{block_type}:**\n>")
-        elif line.startswith(":::"):
-            in_block = False
-        else:
-            cleaned.append(f"> {line}" if in_block else line)
-
-    return "\n".join(cleaned)
-
-def format_value(val_data) -> str:
-    """Formats a value as inline code or a nix code block."""
-    if val_data is None:
-        return None
-
-    if isinstance(val_data, dict) and val_data.get("_type") == "literalMD":
-        return val_data.get("text", "").strip()
-    elif isinstance(val_data, dict) and val_data.get("_type") == "literalExpression":
-        text = val_data.get("text", "").strip()
-    elif isinstance(val_data, bool):
-        text = "true" if val_data else "false"
-    elif val_data == {} or val_data == []:
-        text = "{ }" if val_data == {} else "[ ]"
-    else:
-        text = str(val_data).strip()
-
-    if '\n' in text:
-        return f"\n```nix\n{text}\n```"
-    return f"`{text}`"
-
-def write_section(out, data, title, subtitle):
-    out.write(f"## {title}\n\n{subtitle}\n\n")
-    for key, opt in sorted(data.items()):
-        if key.startswith("_module"):
-            continue
-
-        desc = clean_description(opt.get("description", ""))
-        opt_type = str(opt.get("type", "unknown"))
-        default_val = format_value(opt.get("default"))
-        example_val = format_value(opt.get("example"))
-
-        block = f"### `{key}`\n\n{desc}\n\n**Type:** `{opt_type}`\n\n"
-        if default_val is not None:
-            block += f"**Default:** {default_val}\n\n"
-        if example_val is not None:
-            block += f"**Example:** {example_val}\n\n"
-        block += "---\n\n"
-        out.write(block)
 
 def main():
     if len(sys.argv) != 4:
-        sys.exit("Usage: generate-nix-options-docs.py <nixos.json> <hm.json> <output.md>")
+        sys.exit("Usage: generate-nix-options-docs.py <nixos.md> <hm.md> <output.md>")
 
-    nixos_json, hm_json, output_md = sys.argv[1:4]
-    inputs = [nixos_json, hm_json]
+    nixos_md, hm_md, output_md = sys.argv[1:4]
 
     with open(output_md, 'w', encoding='utf-8') as out:
         out.write(HEADER)
-        for path, section in zip(inputs, SECTIONS):
+        for path, (title, subtitle) in zip([nixos_md, hm_md], SECTIONS):
             with open(path, 'r', encoding='utf-8') as f:
-                data = json.load(f)
-            write_section(out, data, section["title"], section["subtitle"])
-            print(f"Written {section['title']} section.")
+                md = f.read()
+            out.write(f"## {title}\n\n{subtitle}\n\n")
+            out.write(process(md))
+            out.write('\n\n')
+            print(f"Written {title} section.")
+
 
 if __name__ == "__main__":
     main()