Don't process includes within code blocks

Fixes #57

tests/test_llms_txt.py

@@ -198,6 +198,28 @@ def test_process_includes(tmp_path):
     assert processed_content == expected_content
 
 
+def test_process_includes_in_code_block(tmp_path):
+    """Test that an include directive within a code block is not processed."""
+    # Create a processor
+    config = {"llms_txt_directives": []}
+    processor = DocumentProcessor(config)
+
+    # Create a source file that includes the test file
+    source_content = (
+        ".. code-block:: rst\n\n   .. include:: foo.txt"
+    )
+    source_file = tmp_path / "source.txt"
+    with open(source_file, "w", encoding="utf-8") as f:
+        f.write(source_content)
+
+    # Process the include directive
+    processed_content = processor._process_includes(source_content, source_file)
+
+    # Check that the include directive was replaced with the content
+    expected_content = source_content
+    assert processed_content == expected_content
+
+
 def test_process_includes_with_relative_paths(tmp_path):
     """Test that include directives with relative paths are processed correctly."""
     # Create a processor