Remove duplicate References page, link directly to Bibliography

The manual references.md page just redirected to the auto-generated
Bibliography (citelist). Remove it and point the sidebar link directly
to \ref citelist to avoid two near-identical sidebar entries.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: sbryngelson

docs/documentation/readme.md

@@ -35,5 +35,5 @@ Welcome to the Multi-component Flow Code (MFC) documentation.
 ## About
 
 - @ref papers "Papers" - Publications using MFC
-- @ref references "References" - Bibliography
+- \ref citelist "Bibliography" - Cited references
 - @ref authors "Authors" - Contributors