This commit moves the Features page from the section for developers
to the top level in the page tree. This involves:
- Moving the source files to the *features* folder from the *using-scylla* folder.
- Moving images into *features/images* folder.
- Updating references to the moved resources.
- Adding redirections to the moved pages.
Closesscylladb/scylladb#20401
This commit moves the Glossary page to the Reference
section. In addition, it adds the redirection so that
there are no broken links because of this change
and fixes a link to a subsection of Glossary.
Closes#13664
