Fix indentation.

Doc/library/2to3.rst

-
 .. _2to3-reference:
 
 2to3 - Automated Python 2 to 3 code translation
@@ -19,7 +18,7 @@ traverse looking for files with the ``.py`` extension.
 Here is a sample Python 2.x source file, :file:`example.py`::
 
    def greet(name):
-      print "Hello, {0}!".format(name)
+       print "Hello, {0}!".format(name)
    print "What's your name?"
    name = raw_input()
    greet(name)
@@ -65,7 +64,6 @@ changed, but 2to3 cannot fix automatically.  In this case, 2to3 will print a
 warning beneath the diff for a file.
 
 
-
 :mod:`lib2to3` - 2to3's library
 -------------------------------