Just one small thing, i think this sounds better, as a native English speaker: `Webchat cannot be used on #minetest-dev.`

Hmm actually, linking to the homepage and calling that 'official projects' isn't descriptive, the home page doesn't have an 'official projects' section and what is official isn't obvious. How about no link and describing what can be discussed (MTEngine, MTGame), as before?

Makes no sense. `strictly only for discussions of <a href="https://github.com/minetest">official projects'</a> development.`

Almost suggests modding can't be discussed here. `Main channel for general Minetest engine, modding and games discussion or support.`

`You can't use webchat on #minetest-dev` No need for 'the'

instead of saying "you need a real irc client" just say that you "can't use webchat on -dev"

Long sentence, perhaps: `ask an operator for voice, to chat on #minetest-dev you` ?

Maybe 'Minetest engine' here for consistency with the above?

As above, if possible split long line in code.

Line too long in code, can it be split? I assume it auto-wraps when displayed on the webpage.

Is this description any better?

why is the channel name capitalized? this does not reflect their actual names on IRC

quotes not needed

why explicitly name which group of people this channel for?

typo

The channel is not for offtopic; it's simply something we usually accept. I prefer the previous description for -hub, then adjust the other two so they are full sentences.