譯文中rst冒號補回

ref少了冒號，需要將冒號補回來哦哦

Author: asdfghjkl123620

tutorial/introduction.po

@@ -11,7 +11,7 @@ msgstr ""
 "Project-Id-Version: Python 3.6 TW\n"
 "Report-Msgid-Bugs-To: \n"
 "POT-Creation-Date: 2018-06-26 18:54+0800\n"
-"PO-Revision-Date: 2018-06-10 04:13+0000\n"
+"PO-Revision-Date: 2018-07-12 19:57+0800\n"
 "Last-Translator: Ching-Hao Liu <[email protected]>\n"
 "Language-Team: Chinese Traditional (http://www.transifex.com/python-tw-doc/"
 "python-36-tw/language/zh-Hant/)\n"
@@ -20,6 +20,7 @@ msgstr ""
 "Content-Type: text/plain; charset=UTF-8\n"
 "Content-Transfer-Encoding: 8bit\n"
 "Plural-Forms: nplurals=1; plural=0;\n"
+"X-Generator: Poedit 2.0.9\n"
 
 #: ../../tutorial/introduction.rst:5
 msgid "An Informal Introduction to Python"
@@ -443,7 +444,7 @@ msgstr "字串支援非常多種基本轉換和搜尋的方法。"
 
 #: ../../tutorial/introduction.rst:354
 msgid ":ref:`f-strings`"
-msgstr "ref:`f-strings`"
+msgstr ":ref:`f-strings`"
 
 #: ../../tutorial/introduction.rst:354
 msgid "String literals that have embedded expressions."