Added in_use and priority_id field for channels urls. Added priorities table. Setup sql alchemy migration. Generate first migration.

app/main.py

@@ -1,5 +1,5 @@
 
-from app.routers import channels, auth, playlist
+from app.routers import channels, auth, playlist, priorities
 from fastapi import FastAPI
 from fastapi.openapi.utils import get_openapi
 
@@ -55,4 +55,5 @@ async def root():
 # Include routers
 app.include_router(auth.router)
 app.include_router(channels.router)
-app.include_router(playlist.router)
+app.include_router(playlist.router)
+app.include_router(priorities.router)