Add DeepWiki badge at README.md

[birbilis]

I suggest adding the following to README.md:

[![Ask DeepWiki][DeepWikiBadge]](https://deepwiki.com/EtheaDev/SVGIconImageList)

[DeepwikiBadge]: https://deepwiki.com/badge.svg

or

[![Ask DeepWiki](https://deepwiki.com/badge.svg)](https://deepwiki.com/EtheaDev/SVGIconImageList)

that way one will be able to easily click the DeepWiki badge to see info on this repository and also discuss with Devin AI agent there regarding the architecture and the code, bug/enhancements they can do etc.

[birbilis]

corrected the 2nd syntax option above. Will show like below:

[birbilis]

Benefit from having a badge in the README.md is that then DeepWiki rescans the repo often (weekly if I remember well). When not having it visitors need to provide their e-mail and ask for a refresh so they then need to wait or see older info / have the agent discuss on older version