Update to Modus themes stable version 2.7.0

Update to Modus themes stable version 2.7.0

* doc/misc/modus-themes.org (Load theme depending on time of day): Add
missing keyword from sample configuration.
(Full support for packages or face groups): Update list of supported packages.
(Note on goto-address-mode faces): Add documentation about possible
user-level tweaks.
(Are these color schemes?): Fix typo.
(Acknowledgements): Update list of contributors to the project.

* etc/themes/modus-themes.el (modus-themes--version): Update to
current stable version.
(modus-themes-vivendi-colors): Tweak value of a single color.
(modus-themes-faces): Update list of supported faces.
(modus-themes-custom-variables): Remove outdated "TODO" comment.

* etc/themes/modus-operandi-theme.el:
* etc/themes/modus-vivendi-theme.el: Update version header.

Release notes: <https://protesilaos.com/codelog/2022-10-01-modus-themes-2-7-0/>.