add info about how to install the man page as mentioned in #gh-32

README

@@ -57,6 +57,9 @@ NOTES
 
        PROFIT!!
 
+       optionally:
+	install the provided man page z.1 somewhere like /usr/local/man/man1.
+
        Frecency:
 
        Frecency is a portmantaeu of 'recent' and 'frequency'. It  is  a	 weighted
@@ -77,6 +80,8 @@ ENVIRONMENT
 FILES
        data is stored in $HOME/.z
 
+       A man page (z.1) is provided.
+
 
 SEE ALSO
        regex(7), cdargs, pushd, popd, autojump, cdargs