Update description of IRC with newly added channels (#85)

website/chat.md

@@ -14,7 +14,7 @@ head:
 Join our community on the following channels. Before posting, read the rules and the FAQ (usually in the welcome threads or in the signup).
 
 - [Discord Server](https://discord.gg/RjJKA8wrD4).
-- IRC: [`#gbdev` on Libera.chat](https://web.libera.chat/#gbdev). 
-  - `#gbdev-ot`, `#gbdev-hw`,`#gbdev-meta`, `#gbdev-asm`,`#gbdev-gfx`, `#gbdev-emudev` and `#gbdev-research` are also available.
+- IRC: [`#gbdev` on Libera.chat](https://web.libera.chat/#gbdev) is bridged to the Discord chat.
+  - `#gbdev-ot`, `#gbdev-casual`, `#gbdev-hw`, `#gbdev-meta`, `#gbdev-asm`, `#gbdev-gfx`, `#gbdev-emudev`, `#gbdev-romhacking` and `#gbdev-research` are also available for discussion about specific topics.
 - Forum: [https://gbdev.gg8.se/forums](https://gbdev.gg8.se/forums/)
 - Wiki: [https://gbdev.gg8.se/wiki](https://gbdev.gg8.se/wiki/)