[docs] [issue20314] Potentially confusing formulation in 6.1.4. Template strings

Changes by Barry A. Warsaw <barry@python.org>: ---------- versions: +Python 3.7 -Python 2.7, Python 3.3, Python 3.4 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue20314> _______________________________________