use macro for /usr/local/plan9

man/man1/acmeevent.1

@@ -7,7 +7,7 @@ acmeevent, acme.rc \- shell script support for acme clients
 .B acme/acme/$winid/event | acmeevent
 .PP
 .B
-\&. /usr/local/plan9/lib/acme.rc
+\&. \*9/lib/acme.rc
 .PP
 .B newwindow
 .PP
@@ -314,12 +314,12 @@ Typing and button 3 clicking on a word in that window
 will create a new window with the dictionary's entry for that word.
 .PP
 See
-.B /usr/local/plan9/bin/adict
+.B \*9/bin/adict
 for the full implementation.
 .SH SOURCE
-.B /usr/local/plan9/src/cmd/acmeevent.c
+.B \*9/src/cmd/acmeevent.c
 .br
-.B /usr/local/plan9/lib/acme.rc
+.B \*9/lib/acme.rc
 .SH SEE ALSO
 .IR acme (1),
 .IR acme (4),