Doc images

[sdarwin]

The latest docs from 1.88.0 reference a few images which exist in the file system at ../images however the html pages fails to discover them since it's using 1 dot instead of 2.

<img src="./images/posix_exec_err.svg" alt="posix exec err">

Possible relocate the images during the build process so ./images works. Or use ../images/.