minor #5675 [Contributing] add a link to the testing section (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
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[Contributing] add a link to the testing section

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets |

Commits
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399cb5e [Contributing] add a link to the testing section

Author: wouterj

contributing/community/reviews.rst

@@ -173,7 +173,8 @@ Pick a pull request from the `PRs in need of review`_ and follow these steps:
        $ git fetch origin pull/15723/head:pr15723
        $ git checkout pr15723
 
-   Now you can test the project against the code in the PR.
+   Now you can :doc:`test the project </contributing/code/tests>` against
+   the code in the PR.
 
 #. **Update the PR Status**