Enable nested namespace (#951) (#2105)

* Enable nested namespace (#951)

* Specify the namespace as array (#951)

* added an example to the document

Co-authored-by: Alex Crichton <alex@alexcrichton.com>

crates/shared/src/lib.rs

@@ -22,7 +22,7 @@ macro_rules! shared_api {
 
         struct Import<'a> {
             module: ImportModule<'a>,
-            js_namespace: Option<&'a str>,
+            js_namespace: Option<Vec<String>>,
             kind: ImportKind<'a>,
         }