Fix Babel hyperlink in README

Author: stub42

src/README.rst

@@ -520,7 +520,7 @@ Internationalization - i18n/l10n
 
 Pytz is an interface to the IANA database, which uses ASCII names. The `Unicode  Consortium's Unicode Locales (CLDR) <http://cldr.unicode.org>`_
 project provides translations. Python packages such as
-`Babel <https://babel.pocoo.org/en/latest/api/dates.html#timezone-functionality>`
+`Babel <https://babel.pocoo.org/en/latest/api/dates.html#timezone-functionality>`_
 and Thomas Khyn's `l18n <https://pypi.org/project/l18n/>`_ package can be used
 to access these translations from Python.