Localization image handling needs to be updated

[iluwatar]

Currently, the translations (in localization folder) expect to find the images from the parent folder. See for example https://github.com/iluwatar/java-design-patterns/blob/master/localization/zh/abstract-document/README.md?plain=1#L169.

With the new website, the assumption is not true anymore. We should update the image handling so that each localization holds its own copy of the needed images and there is no dependency on the parent.

For example, the line mentioned above should be changed to
![alt text](etc/abstract-document.png "Abstract Document Traits and Domain")
and the image abstract-document.png should be copied into the referenced folder.

[iluwatar]

This is related to issue iluwatar/java-design-patterns-vuepress-web#13

[iluwatar]

Fixed in branch vuepress