Update README.md

Co-Authored-By: Joshua Nelson <jyn514@gmail.com>

Author: pietroalbini

README.md

@@ -64,7 +64,7 @@ cp .env.sample .env
 docker-compose up  # This may take a half hour or more on the first run
 ```
 
-If you need to store big files in the repository's directory is recommended to
+If you need to store big files in the repository's directory it's recommended to
 put them in the `ignored/` subdirectory, which is ignored both by git and
 Docker.