Try this:
routes:
/:
controller: channel
template: index
collections:
/musique/:
permalink: /musique/{slug}/
template: custom-collections
filter: primary_tag:musique
/photo/:
permalink: /photo/{slug}/
template: custom-collections
filter: primary_tag:photo
/moto/:
permalink: /moto/{slug}/
template: custom-collections
filter: primary_tag:moto
/carnets-de-voyage/:
permalink: /carnets-de-voyage/{slug}/
template: custom-collections
filter: primary_tag:carnets-de-voyage
/les-petites-videos/:
permalink: /les-petites-videos/{slug}/
template: custom-collections
filter: primary_tag:les-petites-videos
# NOTE: if you plan on having posts without any of the above primary tags, you need to add a collection here to "catch" the posts that weren't caught by the other filters
taxonomies:
tag: /{slug}/
author: /auteur/{slug}/
I’m not 100% sure if you need to add a filter for the route