[ELPA] New package: consult

[Daniel Mendler]

I want to submit the package "consult" to GNU ELPA. The package is
inspired by Counsel (GNU ELPA), but works with multiple completion UIs,
since it is based on the generic `completing-read` API.

Consult provides is a collection of completion commands, including a
Swiper-like implementation, navigation commands (consult-imenu,
consult-outline) and asynchronous search commands (consult-ripgrep).

Consult works with the default *Completions* UI, Vertico (GNU ELPA),
Selectrum (MELPA), Embark Completions and Icomplete.

The Consult source and an extensive README can be found at
https://github.com/minad/consult.

There are multiple contributors to Consult. The copyright assignment
status has been tracked in https://github.com/minad/consult/issues/75,
see in particular my comment
https://github.com/minad/consult/issues/75#issuecomment-821991990. All
contributors who contributed more than 15 lines have signed the papers.

Thank you!

Daniel Mendler