Fix docker dev db persistence (#264)

* Fix docker dev db persistence

* Make run.sh the only startup script for prod + dev

Credits to @hay-kot for run.sh script logic

* Restore dev backend initialization in non-docker setup

* Make run.sh POSIX-friendly

* Allow dev backend to auto-reload in Docker

mealie/db/init_db.py

@@ -47,11 +47,12 @@ def default_user_init(session: Session):
     logger.info("Generating Default User")
     db.users.create(session, default_user)
 
-
-if __name__ == "__main__":
+def main():
     if sql_exists:
         print("Database Exists")
-        exit()
     else:
         print("Database Doesn't Exists, Initializing...")
         init_db()
+
+if __name__ == "__main__":
+    main()