Do not include leading slash in citation style.

src/parser/citation.rs

@@ -67,10 +67,13 @@ pub(crate) fn citation<'b, 'g, 'r, 's>(
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
 fn citestyle<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
-    let (remaining, _) = tuple((tag("/"), style))(input)?;
-    let (remaining, _) = opt(tuple((tag("/"), variant)))(remaining)?;
-    let source = get_consumed(input, remaining);
-    Ok((remaining, source))
+    map(
+        tuple((
+            tag("/"),
+            recognize(tuple((style, opt(tuple((tag("/"), variant)))))),
+        )),
+        |(_, style)| style,
+    )(input)
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]