Documentation: quoting trouble in "git rm" discussion

The current output (with Asciidoc 8.5.2) seems a bit broken:

	given two directories ‘d` and d2, there is a difference
	between using git rm 'd*’ and ‘git rm 'd/\*\’`, as the
	former will also remove all of directory d2.

In other words, the markup parses as

	given two directories << d` and _d2_, there is a difference
	between using _git rm 'd* >>_ and << git rm 'd/\*\ >> `.

I suspect there is an asciidoc bug involved (why is ' a candidate
closing-quote mark when it is preceded by a backslash?) but with
all the meanings of ` and ' involved I do not want to track it
down.  Better to use unambiguous {asterisk} and {apostrophe}
entities.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/asciidoc.conf

@@ -17,6 +17,7 @@ caret=^
 startsb=[
 endsb=]
 tilde=~
+apostrophe='
 backtick=`
 
 ifdef::backend-docbook[]

Documentation/git-rm.txt

@@ -78,7 +78,8 @@ a file that you have not told git about does not remove that file.
 
 File globbing matches across directory boundaries.  Thus, given
 two directories `d` and `d2`, there is a difference between
-using `git rm \'d\*\'` and `git rm \'d/\*\'`, as the former will
+using `git rm {apostrophe}d{asterisk}{apostrophe}` and
+`git rm {apostrophe}d/{asterisk}{apostrophe}`, as the former will
 also remove all of directory `d2`.
 
 REMOVING FILES THAT HAVE DISAPPEARED FROM THE FILESYSTEM