fix: change urls to make export to pdf works

[franklingu]

currently, there are a few urls with this pattern /docs/...

when trying to covert to pdf for this docsify project, it fails with such errors:

ERROR:
combineMarkdowns

Error: file /docs/micro-services/huifer-what's-microservice-how-to-communicate.md is not exist, but listed in summary.md

by changing "/docs/..." to "./docs/..." the export will work.

What is more, changing of the URLs make URL patterns in summary.md consistent

[franklingu]

this is the npm module to convert to pdf

https://www.npmjs.com/package/docsify-pdf-converter

and here is what I have as the setting

module.exports = {
  contents: [ "summary.md" ], // array of "table of contents" files path
  pathToPublic: "pdf/readme.pdf", // path where pdf will stored
  pdfOptions: "", // reference: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#pagepdfoptions
  removeTemp: true, // remove generated .md and .html or not
  emulateMedia: "screen", // mediaType, emulating by puppeteer for rendering pdf, 'print' by default (reference: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#pageemulatemediamediatype)
}

[franklingu]

我觉得完全可以加上一下export to pdf的相关指导，起码我这种喜欢pdf的会觉得不错