Re: packfile-uri.txt: fix blobPackfileUri description

> Fix the 'uploadpack.blobPackfileUri' description in packfile-uri.txt
> and the correct format also can be seen in t5702.
>
> Signed-off-by: Teng Long <dyroneteng@gmail.com>
> ---
>  Documentation/technical/packfile-uri.txt | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)

> diff --git a/Documentation/technical/packfile-uri.txt b/Documentation/technical/packfile-uri.txt
> index f7eabc6c76..1eb525fe76 100644
> --- a/Documentation/technical/packfile-uri.txt
> +++ b/Documentation/technical/packfile-uri.txt
> @@ -35,13 +35,14 @@ include some sort of non-trivial implementation in the Minimum Viable Product,
>  at least so that we can test the client.
>  
>  This is the implementation: a feature, marked experimental, that allows the
> -server to be configured by one or more `uploadpack.blobPackfileUri=<sha1>
> -<uri>` entries. Whenever the list of objects to be sent is assembled, all such
> -blobs are excluded, replaced with URIs. As noted in "Future work" below, the
> -server can evolve in the future to support excluding other objects (or other
> -implementations of servers could be made that support excluding other objects)
> -without needing a protocol change, so clients should not expect that packfiles
> -downloaded in this way only contain single blobs.
> +server to be configured by one or more `uploadpack.blobPackfileUri=
> +<object-hash> <pack-hash> <uri>` entries. Whenever the list of objects to be
> +sent is assembled, all such blobs are excluded, replaced with URIs. As noted
> +in "Future work" below, the server can evolve in the future to support
> +excluding other objects (or other implementations of servers could be made
> +that support excluding other objects) without needing a protocol change, so
> +clients should not expect that packfiles downloaded in this way only contain
> +single blobs.
>  
>  Client design
>  -------------