fix missing vocab.json and nested packages in pip install

setup.py

@@ -1,4 +1,4 @@
-from setuptools import setup
+from setuptools import setup, find_namespace_packages
 
 setup(
     name="ace_step",
@@ -6,7 +6,7 @@ setup(
     long_description=open("README.md", encoding="utf-8").read(),
     long_description_content_type="text/markdown",
     version="0.1.0",
-    packages=["acestep"],
+    packages=find_namespace_packages(),
     install_requires=open("requirements.txt", encoding="utf-8").read().splitlines(),
     author="ACE Studio, StepFun AI",
     license="Apache 2.0",
@@ -20,4 +20,8 @@ setup(
             "acestep=acestep.gui:main",
         ],
     },
+    include_package_data=True,  # Ensure this is set to True
+    package_data={
+        "acestep.models.lyrics_utils": ["vocab.json"],  # Specify the relative path to vocab.json
+    },
 )