Merge branch 'po/git-help-on-git-itself'

"git help git" was hard to discover (well, at least for some
people).

* po/git-help-on-git-itself:
  Doc: git.txt: remove backticks from link and add git-scm.com/docs
  git.c: show usage for accessing the git(1) help page

git.c

@@ -33,7 +33,8 @@ const char git_usage_string[] =
 const char git_more_info_string[] =
 	N_("'git help -a' and 'git help -g' list available subcommands and some\n"
 	   "concept guides. See 'git help <command>' or 'git help <concept>'\n"
-	   "to read about a specific subcommand or concept.");
+	   "to read about a specific subcommand or concept.\n"
+	   "See 'git help git' for an overview of the system.");
 
 static int use_pager = -1;