refactor(biblio): reformat module

- Defer citar-org, since citar autoloads it.
- Add introducing PR to #+SINCE and use new calver scheme.
- Move <localleader> @ keybind to :lang org

Ref: #5810

modules/lang/org/config.el

@@ -798,6 +798,7 @@ between the two."
         "+" #'org-ctrl-c-minus
         "," #'org-switchb
         "." #'org-goto
+        "@" #'org-cite-insert
         (:when (featurep! :completion ivy)
          "." #'counsel-org-goto
          "/" #'counsel-org-goto-all)