Implement the new fields for LaTeX environment.

src/parser/latex_environment.rs

@@ -57,7 +57,7 @@ where
     let (remaining, _end) = latex_environment_end_specialized(&parser_context, remaining)?;
     let value_end = remaining;
 
-    let (remaining, _trailing_ws) =
+    let (remaining, post_blank) =
         maybe_consume_trailing_whitespace_if_not_exiting(context, remaining)?;
     let source = get_consumed(input, remaining);
     let value = get_consumed(value_start, value_end);
@@ -70,6 +70,7 @@ where
                 affiliated_keywords,
             ),
             value: value.into(),
+            post_blank: post_blank.map(Into::<&str>::into),
         },
     ))
 }