modularize src

+ merge main.py and manage.py
+ move start logic to swingmusic/__main__.py
+ add a run.py on the project root

swingmusic/utils/progressbar.py

@@ -0,0 +1,16 @@
+from tqdm import tqdm as _tqdm
+
+
+def tqdm(*args, **kwargs):
+    """
+    Wrapper for tqdm that sets globals.
+    """
+    bar_format = "{percentage:3.0f}%|{bar:45}|{n_fmt}/{total_fmt}{desc}"
+    kwargs["bar_format"] = bar_format
+
+    if "desc" in kwargs:
+        print(f'INFO|{kwargs["desc"].capitalize()} ...')
+        kwargs["desc"] = ""
+
+
+    return _tqdm(*args, **kwargs)