Add exmaple

Author: hyf0

examples/source_map.rs

@@ -11,7 +11,7 @@ fn main() {
         store_name: true,
         ..Default::default()
     };
-    s
+    s   
         .update_with(
             1,
             2,

src/magic_string/source_map.rs

@@ -63,7 +63,6 @@ impl<'s> MagicString<'s> {
 
     pub fn source_map(&self, opts: SourceMapOptions) -> SourceMap {
         let decoded_map = self.generate_decoded_source_map(opts);
-        println!("decoded_map {decoded_map:#?}");
         decoded_map.into_source_map()
     }
 }

src/mappings.rs

@@ -113,9 +113,9 @@ impl Mappings {
                 vlq::encode(segment.source_index as i64, &mut encoded).unwrap();
                 vlq::encode(segment.original_line as i64, &mut encoded).unwrap();
                 vlq::encode(segment.original_column as i64, &mut encoded).unwrap();
-                // if let Some(name_index) = segment.name_index {
-                //     vlq::encode(name_index as i64, &mut encoded).unwrap();
-                // }
+                if let Some(name_index) = segment.name_index {
+                    vlq::encode(name_index as i64, &mut encoded).unwrap();
+                }
                 encoded_mappings.push_str(&String::from_utf8(encoded).unwrap());
                 if segment_idx != line.len() - 1 {
                     encoded_mappings.push(',');