Re: [PATCH] docs: clarify that credential discards unrecognised attributes

> We did discuss patches a long time ago that would let Git carry
> arbitrary keys between helpers, even if Git itself didn't understand it.
> One of the intended uses was to let helpers talk to each other about
> TTLs. So if you had say:
> 
>   [credential]
>   helper = generate-some-token
>   helper = cache
> 
> where the first helper generates a token, and the second caches it, the
> first one could shove a "ttl" or "expiration" key into the protocol,
> which the cache could then learn to respect.