Get the real language for src blocks from the org source.

src/context/src_block.rs

@@ -11,10 +11,12 @@ use super::macros::render;
 #[serde(rename = "src_block")]
 pub(crate) struct RenderSrcBlock {
     lines: Vec<String>,
+    language: Option<String>,
 }
 
 render!(RenderSrcBlock, ISrcBlock, original, _render_context, {
     Ok(RenderSrcBlock {
         lines: original.lines.clone(),
+        language: original.language.clone(),
     })
 });