doc: trailer: swap verb order

This matches the order already used in the NAME section.

Signed-off-by: Linus Arver <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: Linus Arver

Documentation/git-interpret-trailers.txt

@@ -14,7 +14,7 @@ SYNOPSIS
 
 DESCRIPTION
 -----------
-Parse or add 'trailer' lines that look similar to RFC 822 e-mail
+Add or parse 'trailer' lines that look similar to RFC 822 e-mail
 headers, at the end of the otherwise free-form part of a commit
 message.