ändert Kommentare von libex01 zu Docstring

src/libex01.py

@@ -1,10 +1,14 @@
-# file: read_plaintext.py
-# module to read plaintext from a file into a string variable.
-# Skips non-alphabetic characters and converts the rest to lower case
+"""
+module to encapsulate common functions for exercise01.
+"""
 
 import string
 
 def read_plaintext(file_path):
+    """
+    funciton to read plaintext from a file into a string variable.
+    Skips non-alphabetic characters (including whitespace) and converts the rest to lower case.
+    """
     txt = ""
     with open(file_path, "r") as _file:
         for line in _file: