Use regex for alert content smart filter

This function is going to need the re module for more complex tasks
shortly, so go ahead and start using it for this too.

weather.py

@@ -336,10 +336,11 @@ def get_alert(
     if alert:
         if verbose: return alert
         else:
-            if alert.find("\nNational Weather Service") == -1:
-                muted = False
-            else:
+            import re
+            if re.search(r"\nNational Weather Service", alert):
                 muted = True
+            else:
+                muted = False
             lines = alert.split("\n")
             import time
             # TODO: make this offset configurable