files: minor comments in digest

gargantext/util/digest.py

+"""
+Creates MD5 hashes (used for unique filepaths)
+NB this module could go inside util.files
+"""
+
 import hashlib
 import binascii
 
 
 def digest(value, algorithm='md5'):
+    """
+    Ex: b'm\x00\x07\xe5/z\xfb}Z\x06P\xb0\xff\xb8\xa4\xd1'
+
+    (16 bytes ranging from 0 to ff)
+    """
     m = hashlib.new(algorithm)
     m.update(value)
     return m.digest()
 
 def str_digest(value, algorithm='md5'):
+    """
+    Ex: 6d0007e52f7afb7d5a0650b0ffb8a4d1
+
+    (32 hex chars)
+    """
     return binascii.hexlify(digest(value, algorithm)).decode()