feat(manifest:npm:esm): add sideeffects key, set to false

src/manifest/mod.rs

@@ -181,6 +181,7 @@ impl CargoManifest {
             files: files,
             module: js_file,
             types: dts_file,
+            sideEffects: "false".to_string(),
         })
     }
 }

src/manifest/npm/esmodules.rs

@@ -17,4 +17,5 @@ pub struct ESModulesPackage {
     pub module: String,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub types: Option<String>,
+    pub sideEffects: String,
 }