Update video links
ateliers/samba-ad.md: Fix link
ateliers/index.md: Fix typo
Finish replacing Dailymotion links
gazette/bluehats_9.md: Replace video link
Use tube.numerique.gouv.fr for videos
Minor typo fixes
gazette/bluehats_20.md: Add link
gazette/bluehats_20.md: Add link to article
gazette/bluehats_20.md: Small tweak
gazette/bluehats_20.md: Minor update
Publish BlueHats gazette n°20
Publish the action plan in english
rencontres/journee-2022.md: Add link to slides