Add default path for user configuration

borgmatic/config/collect.py

@@ -1,7 +1,8 @@
 import os
 
 
-DEFAULT_CONFIG_PATHS = ['/etc/borgmatic/config.yaml', '/etc/borgmatic.d']
+DEFAULT_CONFIG_PATHS = ['/etc/borgmatic/config.yaml', '/etc/borgmatic.d',
+                        os.path.expanduser('~/.config/borgmatic/config.yaml')]
 
 
 def collect_config_filenames(config_paths):