docs: fix the ". ::" sentences and merge them into "::" directly

Author: Mr-Sunglasses

Doc/library/urllib.request.rst

@@ -1213,7 +1213,7 @@ In addition to the examples below, more examples are given in
 :ref:`urllib-howto`.
 
 This example gets the python.org main page and displays the first 300 bytes of
-it. ::
+it::
 
    >>> import urllib.request
    >>> with urllib.request.urlopen('http://www.python.org/') as f:
@@ -1232,7 +1232,7 @@ the various ways in which an HTML document could have specified its
 encoding information.
 
 As the python.org website uses *utf-8* encoding as specified in its meta tag, we
-will use the same for decoding the bytes object. ::
+will use the same for decoding the bytes object::
 
    >>> with urllib.request.urlopen('http://www.python.org/') as f:
    ...     print(f.read(100).decode('utf-8'))
@@ -1242,7 +1242,7 @@ will use the same for decoding the bytes object. ::
    <!-
 
 It is also possible to achieve the same result without using the
-:term:`context manager` approach. ::
+:term:`context manager` approach::
 
    >>> import urllib.request
    >>> f = urllib.request.urlopen('http://www.python.org/')