mentionln
inline fun EntitiesBuilder.mentionln(parts: TextSourcesList, userId: UserId): EntitiesBuilder(source)
inline fun EntitiesBuilder.mentionln(userId: UserId, vararg parts: TextSource): EntitiesBuilder(source)
Version of EntitiesBuilder.mention with new line at the end
Version of EntitiesBuilder.mention with new line at the end. Will reuse separator config from buildEntities