Feat: configure neomutt, khard and vdirsyncer

neomutt/.config/vdirsyncer/config

@@ -0,0 +1,21 @@
+[general]
+status_path = "~/.config/vdirsyncer/status/"
+
+[pair cloud_opytex_contact]
+a = "cloud_opytex_contact_local"
+b = "cloud_opytex_contact_remote"
+collections = ["from a", "from b"]
+conflict_resolution = "b wins"
+
+[storage cloud_opytex_contact_local]
+type = "filesystem"
+path = "~/.contacts/"
+fileext = ".vcf"
+
+[storage cloud_opytex_contact_remote]
+type = "carddav"
+
+# We can simplify this URL here as well. In theory it shouldn't matter.
+url = "https://cloud.poneyworld.net/remote.php/dav/addressbooks/users/lafrite/contacts/"
+username = "lafrite"
+password.fetch = ["command", "pass", "OVH/Panais/docker/cloud.poneyworld.net/lafrite"]