Add default list setting (#875)

Co-authored-by: Sytone <github@sytone.com>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/875
Reviewed-by: konrad <konrad@kola-entertainments.de>
Co-authored-by: sytone <kolaente@sytone.com>
Co-committed-by: sytone <kolaente@sytone.com>

pkg/swagger/docs.go

@@ -8556,6 +8556,10 @@ var doc = `{
         "v1.UserSettings": {
             "type": "object",
             "properties": {
+                "default_list_id": {
+                    "description": "If a task is created without a specified list this value should be used. Applies\nto tasks made directly in API and from clients.",
+                    "type": "integer"
+                },
                 "discoverable_by_email": {
                     "description": "If true, the user can be found when searching for their exact email.",
                     "type": "boolean"