Display the readme on the repo's start page

It has some text in it. If your repo contains a markdown file called README.md, it will be shown here.

## TODOs

- [x] Display the readme on the repo home page
- [ ] Syntax highlighting (highlight.js?)

  eleventyConfig.addAsyncFilter("getReadMe", async (repoName) => {
    const res = await exec(`(cd ${darcsConfig.repos[repoName].location}; darcs show contents README.md)`)
    return res.stdout
  })

{{ repo | getReadMe | renderContent("md") | safe }}