doc: fix unquoted use of "{type}"

Curly braces open an "attribute" in AsciiDoc; if there's no
such attribute, strange things may happen. In this case, the
unquoted "{type}" causes AsciiDoc to omit an entire line of
text from the output. We can fix it by putting the whole
phrase inside literal backticks (which also lets us get rid
of ugly backslash escaping).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-rev-parse.txt

@@ -102,7 +102,7 @@ eval "set -- $(git rev-parse --sq --prefix "$prefix" "$@")"
 +
 If you want to make sure that the output actually names an object in
 your object database and/or can be used as a specific type of object
-you require, you can add "\^{type}" peeling operator to the parameter.
+you require, you can add the `^{type}` peeling operator to the parameter.
 For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR`
 names an existing object that is a commit-ish (i.e. a commit, or an
 annotated tag that points at a commit).  To make sure that `$VAR`