Release 0.4

- ob-arduino.el: https://repo.or.cz/arduino-mode.git/blob/HEAD:/ob-arduino.el
- ob-clojure-literate.el: https://repo.or.cz/ob-clojure-literate.el.git
- ob-mathematica.el: https://github.com/tririver/ob-mathematica/
- ob-php.el: https://repo.or.cz/ob-php.git
- ob-redis.el: https://repo.or.cz/ob-redis.git
- ob-sclang.el: https://repo.or.cz/ob-sclang.git
- ob-smiles.el: https://repo.or.cz/ob-smiles.git
- ob-spice.el: https://repo.or.cz/ob-spice.git
- ob-stan.el: https://git.kyleam.com/ob-stan
- ol-notmuch.el: https://git.sr.ht/~tarsius/ol-notmuch
- org-attach-embedded-images.el: https://gitlab.com/marcowahl/org-attach-embedded-images
- org-contacts.el: https://repo.or.cz/org-contacts.git
- org-link-edit.el: https://git.kyleam.com/org-link-edit/about
- org-mac-link.el: https://gitlab.com/aimebertrand/org-mac-link
- org-notify.el: https://github.com/p-m/org-notify
- org-passwords.el: https://github.com/alfaromurillo/org-passwords.el
- org-velocity.el: https://github.com/ruricolist/org-velocity
- ox-rss.el: https://gitlab.com/nsavage/ox-rss