fix: warn on missing included file

Author: cestef

components/markdown/src/codeblock/mod.rs

@@ -137,8 +137,13 @@ impl<'config> CodeBlock<'config> {
     pub fn include(&self, base: Option<&PathBuf>) -> Option<String> {
         let path = base?.join(self.include.as_ref()?);
         let res = read_file(&path);
-
-        res.ok()
+        match res {
+            Ok(content) => Some(content),
+            Err(e) => {
+                eprintln!("Warning: Failed to include {:?}: {}", path, e);
+                None
+            }
+        }
     }
 
     pub fn highlight(&mut self, content: &str) -> String {