Fix: 404 Link on git workflow docs. (#55897)

docs/contributors/code/git-workflow.md

@@ -23,7 +23,7 @@ See the [repository management document](/docs/contributors/repository-managemen
 
 ## Git Workflow Walkthrough
 
-The workflow for code and documentation is the same, since both are managed in GitHub. You can watch a [video walk-through of contributing documentation](https://wordpress.tv/2020/09/02/marcus-kazmierczak-contribute-developer-documentation-to-gutenberg/) and the accompanying [slides for contributing to Gutenberg](https://mkaz.blog/wordpress/contribute-documentation-to-gutenberg/).
+The workflow for code and documentation is the same, since both are managed in GitHub. You can watch a [video walk-through of contributing documentation](https://wordpress.tv/2020/09/02/marcus-kazmierczak-contribute-developer-documentation-to-gutenberg/) and the accompanying [tutorial for contributing to Gutenberg](https://mkaz.blog/wordpress/contribute-developer-documentation-to-gutenberg/).
 
 Here is a visual overview of the Git workflow: