use my.config instead of mycfg; minor cleanups and docstrings

my/feedbin.py

@@ -5,7 +5,7 @@ Module for Feedbin RSS reader
 from .common import listify
 from ._rss import Subscription
 
-from mycfg import paths
+from my.config import feedbin as config
 
 import json
 from pathlib import Path
@@ -27,7 +27,8 @@ def parse_file(f: Path):
 
 def get_states() -> Dict[datetime, List[Subscription]]:
     res = {}
-    for f in sorted(Path(paths.feedbin.export_dir).glob('*.json')):
+    # TODO use get_files
+    for f in sorted(Path(config.export_dir).glob('*.json')):
         dts = f.stem.split('_')[-1]
         dt = isoparse(dts)
         subs = parse_file(f)