Mkdocs officially only supports relative links. While this makes sense there are situation where it is useful to make use of absolute links. For example when creating a document with absolute links to an image folder. If that file is to be moved later on, links are kept intact.

pip install mkdocs-abs-rel-plugin

In your mkdocs.yml file add abs-to-rel to the plugins entry:

plugins:
  - abs-to-rel