Add Command Line Reference to readthedocs (#102)

Fixes shader-slang/slang#7021

This change adds the slangc command line reference to the ReadTheDocs site, replacing the link to the .md file in the repo.

The current doc is encoded as UTF-16LE, unlike our other docs in UTF-8, and although my other change for this issue (shader-slang/slang#7048) does have a regenerated version in UTF-8, this change also adds a pre-processing step to the RTD build that re-encodes any UTF-16LE doc to UTF-8 just in case.

Author: aidanfnv

docs/conf.py

@@ -9,6 +9,7 @@
 import os
 import sys
 import re
+from pathlib import Path
 
 sys.path.insert(0, os.path.abspath('.'))  # For finding _ext
 sys.path.insert(0, os.path.abspath('..'))
@@ -25,9 +26,24 @@ def uncomment_toc(match):
     new_content = pattern.sub(uncomment_toc, content)
     source[0] = new_content
 
+def handle_utf16le_files(app, docname, source):
+    doc_path = Path(app.env.doc2path(docname))
+
+    with open(doc_path, 'rb') as f:
+        content_bytes = f.read()
+        
+        # Check for UTF-16LE BOM (FF FE)
+        if content_bytes.startswith(b'\xff\xfe'):
+            # Decode from UTF-16LE
+            content = content_bytes.decode('utf-16le')
+            # Strip any BOM characters that might be present as text
+            content = content.replace('\ufeff', '')
+            # Set the source content
+            source[0] = content
+
 def setup(app):
-    # Connect the handler to the 'source-read' event
     app.connect('source-read', source_read_handler)
+    app.connect('source-read', handle_utf16le_files)
 
 project = 'Slang Documentation'
 author = 'Chris Cummings, Benedikt Bitterli, Sai Bangaru, Yong Hei, Aidan Foster'
@@ -69,6 +85,7 @@ def setup(app):
 ]
 include_patterns = ['index.rst', '*.md',
                     "external/slang/docs/user-guide/*.md",
+                    "external/slang/docs/command-line-slangc-reference.md",
                     "external/core-module-reference/index.md",
                     "external/core-module-reference/attributes/**",
                     "external/core-module-reference/global-decls/**",

docs/index.rst

@@ -11,7 +11,7 @@ Slang Documentation
    Language Spec <https://github.com/shader-slang/spec>
    SlangPy User Guide <external/slangpy/docs/index.rst>
    Feature Matureness <feature_matureness>
-   Command Line Reference <https://github.com/shader-slang/slang/blob/master/docs/command-line-slangc-reference.md>
+   Command Line Reference <external/slang/docs/command-line-slangc-reference>
    Frequently Asked Questions <faq>
 
 .. toctree::