DOC: fix links

Author: jreback

doc/source/whatsnew/v0.17.1.txt

@@ -9,9 +9,9 @@ We recommend that all users upgrade to this version.
 
 Highlights include:
 
-  - Support for Conditional HTML Formatting, see :ref:`here <whatsnew_0171.style>`
-  - Releasing the GIL on the csv reader & other ops, see :ref:`here <whatsnew_0171.performance>`
-  - Regression in ``DataFrame.drop_duplicates`` from 0.16.2, causing incorrect results on integer values (:issue:`11376`)
+- Support for Conditional HTML Formatting, see :ref:`here <whatsnew_0171.style>`
+- Releasing the GIL on the csv reader & other ops, see :ref:`here <whatsnew_0171.performance>`
+- Regression in ``DataFrame.drop_duplicates`` from 0.16.2, causing incorrect results on integer values (:issue:`11376`)
 
 .. contents:: What's new in v0.17.1
     :local:
@@ -20,7 +20,7 @@ Highlights include:
 New features
 ~~~~~~~~~~~~
 
-.. _whatsnew_0171.style
+.. _whatsnew_0171.style:
 
 Conditional HTML Formatting
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^