Documentation: rename gitlink macro to linkgit

Documentation: rename gitlink macro to linkgit

Between AsciiDoc 8.2.2 and 8.2.3, the following change was made to the stock
Asciidoc configuration:

@@ -149,7 +153,10 @@
 # Inline macros.
 # Backslash prefix required for escape processing.
 # (?s) re flag for line spanning.
-(?su)[\\]?(?P<name>\w(\w|-)*?):(?P<target>\S*?)(\[(?P<attrlist>.*?)\])=
+
+# Explicit so they can be nested.
+(?su)[\\]?(?P<name>(http|https|ftp|file|mailto|callto|image|link)):(?P<target>\S*?)(\[(?P<attrlist>.*?)\])=
+
 # Anchor: [[[id]]]. Bibliographic anchor.
 (?su)[\\]?\[\[\[(?P<attrlist>[\w][\w-]*?)\]\]\]=anchor3
 # Anchor: [[id,xreflabel]]

This default regex now matches explicit values, and unfortunately in this
case gitlink was being matched by just 'link', causing the wrong inline
macro template to be applied. By renaming the macro, we can avoid being
matched by the wrong regex.

Signed-off-by: Dan McGee <dpmcgee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>