image url begin with "/" should be AbsolutePath，not RelativePath about docsify

[Koooooo-7]

Hi @poerlang , thx for your report!
We already raised this issue in #1891, we still discuss on how to refactor its behavior and keep the things work more as expectation.

[jhildenbiddle]

Bug acknowledged. Tracking with #1891.

[poerlang]

the regular expression in isAbsolutePath function only considers the cases ofhttp://or https://, but does not take into account URLs that start with /, so the bug happen

var isAbsolutePath = cached(function (path) {
    return /(:|(\/{2}))/g.test(path);
  });