[spec] Limit valid encodings of text/gemini to UTF-8

[Petite Abeille]

> On Dec 30, 2020, at 03:31, Peter Vernigorov <pitr.vern at gmail.com> wrote:
> 
> , the oft quoted part of the spec is in section “3.3 Response bodies” and talks about any text/* responses.

Ohhhh... right you are, I was assuming text/gemini only. My bad.

This sounds like a major overreach. Shouldn't Gemini restrict itself to just text/gemini as far as the Gemini spec goes?

On what ground would Gemini redefine what a text content type is?

A MIME content type of "text" is "text/plain; charset=us-ascii" by default. 

I don't quite see the point of redefining how a major piece of MIME is defined. Sounds counterproductive.