fixed a small typo in the doc (#11856)

CONTRIBUTING.md

@@ -37,7 +37,7 @@ There are 4 ways you can contribute to transformers:
 * Submitting issues related to bugs or desired new features.
 
 In particular there is a special [Good First
-Issue](https://github.com/huggingface/transformers/contribute) listing. Tt will give you a list of
+Issue](https://github.com/huggingface/transformers/contribute) listing. It will give you a list of
 open Issues that are open to anybody to work on. Just comment in the issue that you'd like to work
 on it. In that same listing you will also find some Issues with `Good Second Issue` label. These are
 typically slightly more complicated than the Issues with just `Good First Issue` label. But if you