Remove 'Invalid command response

bot/response.py

@@ -94,7 +94,6 @@ def do_create(full_user, arguments, note_obj):
     )
     return([f'{full_user}Added {arguments[0]}, ID {character_id}.',[file_id]])
 
-
 def do_help(full_user):
     '''Provides a list of commands that the bot can do.'''
     return f'{full_user} Here\'s what I can do:\n \
@@ -102,11 +101,6 @@ def do_help(full_user):
             - `create <name> <rarity> <weight>` Creates a character using a given image.\
             - `help` Shows this message'
 
-def do_invalid_command(command, full_user):
-    '''Generic response when an unknown or invalid command is sent'''
-    return f'{full_user} Unrecognised command: {command}\n\
-            Message \'help\' to get a list of valid commands'
-
 def generate_response(parsed_command):
     '''Given a command with arguments, processes the game state and
     returns a response'''
@@ -120,4 +114,4 @@ def generate_response(parsed_command):
         case 'help':
             return do_help(command)
         case _:
-            return do_invalid_command(command, full_user)
+            return None