Fix spelling

CONTRIBUTING.md

@@ -131,7 +131,7 @@ To do this, there are a few requirements that all notebooks need to pass.
 4. Don't use HTML for text cells, use Markdown markups instead.
 5. Add **Table of content** to top of the Notebook, it helps to get quick fist understanding of content and ease of navigation in the dev environment. There is no need to think about it during development, it can be built or updated after changes with `.ci\table_of_content.py`. Just run the script with the parameter `-s/--source`, specifying a Notebook or a folder with several notebooks as value, the changes will be applied to all of them.
 6. Add **Installation Instructions** section to the top of the notebook (after "Table of content") and to the corresponding README file in the notebook directory. See existing notebooks for the reference.
-7. Add Scarf Pixel tag for analytics to the notebook (at the end of the first cell) and to the corresponding README file (to the end of the file). Add relative path to the notebook or README file as `path` URL query parameter. Example: `<img referrerpolicy="no-referrer-when-downgrade" src="https://static.scarf.sh/a.png?x-pxid=5b5a4db0-7875-4bfb-bdbd-01698b5b1a77&file=<RELATIVE_FILE_PATH>" />`.
+7. Add Scarf Pixel tag for analytics to the notebook (at the end of the first cell) and to the corresponding `README.md` file (to the end of the file). Add relative path to the notebook or `README.md` file as `path` URL query parameter. Example: `<img referrerpolicy="no-referrer-when-downgrade" src="https://static.scarf.sh/a.png?x-pxid=5b5a4db0-7875-4bfb-bdbd-01698b5b1a77&file=<RELATIVE_FILE_PATH>" />`.
 8. In case if notebook has specific requirements on python version or OS, it should be noted on top of notebook (before any code blocks) using
    following colored block:
    ```