Relative images in YAML front matter handling in custom layout

[imfing]

Simply, I want to load images from paths relative to the README.md directory in a custom layout.

Beause in some cases (customized layouts), image resouces couldn't always be placed under the .vuepress/public directory or loaded with markdown.

For example, the title/background image for a blog post.
So I'm wondering what's the best practice to achieve so with vuepress.

In my case, the yaml front matter of the README.md would expected to be something like:

# README.md
---
avatar: ./path1/image.png  # relative to README.md
background: ./path2/image.png
layout: Post
---

And the Post.vue would be like:

<template>
  <div>
    <img :src="data.avatar">
    <Content/>
  <div>
</template>

However, the image isn't being parsed and loaded correctly since vuepress only injected its .vuepress/public path and copied them with copy-plugin. Also, webpack didn't handle the resources in yaml front matter.

Node.js v8.7.0
VuePress 1.7.0

[imfing]

Sorry, duplicate of issue #79