Fix all pylint warnings

histd.py

@@ -1,4 +1,10 @@
 #!/usr/bin/env python3
+
+"""
+Histd: how I spent this day.
+A simple but useful personal diary CLI utility.
+"""
+
 from datetime import date
 import os
 import subprocess
@@ -6,6 +12,10 @@ import sys
 
 
 def main():
+    """
+    Main function, run first.
+    Prepares environment and parses commands.
+    """
     base_dir = get_base_dir()
     today = date.today()
 
@@ -94,7 +104,7 @@ def merge(base_dir: str):
                 strings.append(res)
             # It's a file
             else:
-                with open(entry_path, 'r') as note:
+                with open(entry_path, 'r', encoding='utf-8') as note:
                     strings.append(f'## {entry_path}')
                     strings.append(note.read())