doc: gitprotocol-pack: improve paragraphs structure

Logically separate the introductory sentence from the first transport
description to improve readability and structural clarity.

Signed-off-by: LorenzoPegorari <lorenzo.pegorari2002@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: LorenzoPegorari

Documentation/gitprotocol-pack.adoc

@@ -47,7 +47,9 @@ process defined in this protocol is terminated.
 Transports
 ----------
 There are three transports over which the packfile protocol is
-initiated.  The Git transport is a simple, unauthenticated server that
+initiated.
+
+The Git transport is a simple, unauthenticated server that
 takes the command (almost always 'upload-pack', though Git
 servers can be configured to be globally writable, in which 'receive-
 pack' initiation is also allowed) with which the client wishes to