bug#54190: 29.0.50; [PATCH] Incorrect/missing documentation for some Eshell "$" syntaxes

[Jim Porter]

On 2/27/2022 1:34 PM, Jim Porter wrote:
> In fact, what "$<FOO>" does is to run FOO as a subcommand, writing its 
> stdout to a temp file, and returning that file's name.
Hmm, that's unfortunate. It seems that the "$<FOO>" syntax in Eshell 
broke sometime between 27.2 and 28. I'm bisecting to figure out where 
that happened, but figured I'd mention it now so there's no confusion if 
someone tries it out now on 28/29. Fix forthcoming (hopefully).