Upgrade comment and documentation for block comment

See https://github.com/PyCQA/pycodestyle/issues/1034\#issuecomment-962454974

Author: Pierre-Sassoulas

pycodestyle.py

@@ -1062,12 +1062,14 @@ def whitespace_before_comment(logical_line, tokens):
     Inline comments should be separated by at least two spaces from the
     statement. They should start with a # and a single space.
 
-    Each line of a block comment starts with a # and a single space
-    (unless it is indented text inside the comment).
+    Each line of a block comment starts with a # and one or multiple
+    spaces as there can be indented text inside the comment.
 
     Okay: x = x + 1  # Increment x
     Okay: x = x + 1    # Increment x
-    Okay: # Block comment
+    Okay: # Block comments:
+    Okay: #  - Block comment list
+    Okay: #  - Block comment list
     E261: x = x + 1 # Increment x
     E262: x = x + 1  #Increment x
     E262: x = x + 1  #  Increment x