Pug: relative include/extends in templates

[rsify]

Using the include/exclude keywords inside of pug <template>'s as following:

<!-- component.vue -->
<template lang="pug">
div
  h1 This is the app
  include ./pug-included
  comp-a
  comp-b
</template>

// pug-included.pug
div Included content

...did not work before, as you ought to provide the filename option to pug's .compile() method to use those features.