modularize src

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

swingmusic/lib/pydub/.github/issue_template.md

@@ -0,0 +1,17 @@
+### Steps to reproduce
+
+### Expected behavior
+Tell us what should happen
+
+### Actual behavior
+Tell us what happens instead
+
+### Your System configuration
+- Python version: 
+- Pydub version: 
+- ffmpeg or avlib?: 
+- ffmpeg/avlib version: 
+
+### Is there an audio file you can include to help us reproduce?
+You can include the audio file in this issue - just put it in a zip file and drag/drop the zip file into the github issue.
+