Readme: Reintroduce irc ahain
The current build status is:
Gitter chat: [![Join the chat at https://gitter.im/assimp/assimp](https://badges.gitter.im/assimp/assimp.svg)](https://gitter.im/assimp/assimp?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)<br>
+And we also have an IRC-channel at freenode: #assetimporterlib . You can easily join us via: [KiwiIRC/freenote](https://kiwiirc.com/client/irc.freenode.net), choose your nickname and type
+> /join #assetimporterlib
+<br>
__[open3mod](https://github.com/acgessler/open3mod) is a powerful 3D model viewer based on Assimp's import and export abilities.__
Please check our Wiki as well: https://github.com/assimp/assimp/wiki