A proposed scheme for parsing preformatted alt text

[Sean Conner]

It was thus said that the Great A. E. Spencer-Reed once stated:
> When parsing closing lines with extra text after the "```", should
> they just be treated as part of the block? ex. should
> ```Alt Text
> 1
> ```2
> 3
> ```
> 4
> 
> look like
> +------------------------------+
> | 1                            |
> | ```2                         |
> | 3                            |
> +------------------------------+
> 4
> 
> or
> 
> +------------------------------+
> | 1                            |
> +------------------------------+
> 3
> +------------------------------+
> | 4                            |
> +------------------------------+

  The second example.  From the spec
(gemini://gemini.circumlunar.space/docs/specification.gmi):

	Any text following the leading "`" of a preformat toggle line which
	toggles preformatted mode off MUST be ignored by clients.

  -spc