Split lang on tab to be consistent with rustdoc and GitHub.

src/utils/mod.rs

@@ -231,7 +231,7 @@ fn clean_codeblock_headers(event: Event<'_>) -> Event<'_> {
             let info: String = info
                 .chars()
                 .map(|x| match x {
-                    ' ' => ',',
+                    ' ' | '\t' => ',',
                     _ => x,
                 })
                 .filter(|ch| !ch.is_whitespace())