This commit removes two redundant pages and adds the related redirections. - The Tutorials page is a duplicate and is not maintained anymore. Having it in the docs hurts the SEO of the up-to-date Tutorias page. - The Contributing page is not helpful. Contributions-related information should be maintained in the project README file. Fixes https://github.com/scylladb/scylladb/issues/17279 Fixes https://github.com/scylladb/scylladb/issues/24060 Closes scylladb/scylladb#24090