Fix issue tracker links in contribution guide.

docs/CONTRIBUTING.rst

@@ -5,13 +5,13 @@ If you are looking for a good way to contribute to the Cython project, please
 
 * have a look at the `Cython Hacker Guide <https://github.com/cython/cython/wiki/HackerGuide>`_,
   especially the section on `getting started <https://github.com/cython/cython/wiki/HackerGuide#getting-started>`_.
-* look through the `issues that need help <https://github.com/cython/cython/issues?q=is%3Aissue+is%3Aopen+view+label%3A%22help+wanted%22>`_.
-* look through the `issues that are a good entry point for beginners <https://github.com/cython/cython/issues?q=is%3Aissue+is%3Aopen+view+label%3A%22good+first+issue%22>`_.
+* look through the `issues that need help <https://github.com/cython/cython/issues?utf8=%E2%9C%93&q=is%3Aissue+is%3Aopen+label%3A%22help+wanted%22>`_.
+* look through the `issues that are a good entry point for beginners <https://github.com/cython/cython/issues?utf8=%E2%9C%93&q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22+>`_.
 * ask on the `core developers mailing list <https://mail.python.org/mailman/listinfo/cython-devel>`_ for guidance.
 
 If you have code that you want to contribute, please make sure that it
 
-* includes tests in the `tests/` directory (see the `Hacker Guide on Testing <https://github.com/cython/cython/wiki/HackerGuide#the-test-suite>`_)
+* includes tests in the ``tests/`` directory (see the `Hacker Guide on Testing <https://github.com/cython/cython/wiki/HackerGuide#the-test-suite>`_)
 * comes in form of a pull request
 
 We use `travis <https://travis-ci.org/cython/cython>`_ and `appveyor <https://ci.appveyor.com/project/cython/cython>`_ for cross-platform testing, including pull requests.