- 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
- Rename module from `:completion selectrum` to `:completion vertico`
- Rename all files involved
- Do *not* yet rename all the functions, as that messes up git's rename
detection.
Helm-Bibtex was split to extract bibtex-completion into a standalone
MELPA package. Adding the functionality here to account for the
changes in the packaging.