feat: add (incomplete) nix flake

dave.py isn't packaged yet. Will try to do this myself but dealing with
vcpkg is a bit annoying.

errornocord/main.py

@@ -0,0 +1,24 @@
+import logging
+
+from . import constants, events
+from .state import client
+
+
+def main():
+    logging.basicConfig(
+        format=(
+            "%(asctime)s %(levelname)s %(name)s:%(module)s %(message)s"
+            if __debug__
+            else "%(asctime)s %(levelname)s %(message)s"
+        ),
+        datefmt="%Y-%m-%d %T",
+        level=logging.DEBUG if __debug__ else logging.INFO,
+    )
+    logging.getLogger("disnake").setLevel(logging.WARNING)
+
+    events.prepare()
+    client.run(constants.SECRETS["TOKEN"])
+
+
+if __name__ == "__main__":
+    main()