Update index.html
Update index.html

Removed link to removed packaging chapter.
dskecse/rust_for_rubyists,gpbonillas/rust_for_rubyists,steveklabnik/rust_for_rubyists,dskecse/rust_for_rubyists,steveklabnik/rust_for_rubyists,gpbonillas/rust_for_rubyists,steveklabnik/rust_for_rubyists,dskecse/rust_for_rubyists,gpbonillas/rust_for_rubyists