Install README too.

Unfortunately pup doesn't have any man page. However, README.md is
a good introduction to it so install it in `share/doc/pup' so that binary
package users can easily access it.

Bump PKGREVISION.

Index: Makefile
===================================================================
RCS file: /cvsroot/pkgsrc/www/pup/Makefile,v
retrieving revision 1.2
diff -u -p -r1.2 Makefile
--- Makefile	13 Apr 2017 15:12:06 -0000	1.2
+++ Makefile	8 May 2017 07:48:26 -0000
@@ -1,7 +1,7 @@
 # $NetBSD: Makefile,v 1.2 2017/04/13 15:12:06 bsiegert Exp $
 
 DISTNAME=		pup-0.4.0
-PKGREVISION=		1
+PKGREVISION=		2
 CATEGORIES=		www
 MASTER_SITES=		${MASTER_SITE_GITHUB:=ericchiang/}
 GITHUB_TAG=		v${PKGVERSION_NOREV}
@@ -18,7 +18,7 @@ WRKSRC=			${WRKDIR}/src/github.com/ericc
 BUILD_DEPENDS+=		go-${GO_VERSION}*:../../lang/go
 
 MAKE_ENV+=		GOPATH=${WRKDIR}:${PREFIX}/gopkg
-INSTALLATION_DIRS+=	bin
+INSTALLATION_DIRS+=	bin share/doc/pup
 
 post-extract:
 	${MKDIR} ${WRKSRC}
@@ -29,5 +29,6 @@ do-build:
 
 do-install:
 	${INSTALL_PROGRAM} ${WRKSRC}/bin/pup ${DESTDIR}${PREFIX}/bin
+	${INSTALL_DATA} ${WRKSRC}/README.md ${DESTDIR}${PREFIX}/share/doc/pup/README
 
 .include "../../mk/bsd.pkg.mk"
Index: PLIST
===================================================================
RCS file: /cvsroot/pkgsrc/www/pup/PLIST,v
retrieving revision 1.1
diff -u -p -r1.1 PLIST
--- PLIST	17 Feb 2017 15:39:38 -0000	1.1
+++ PLIST	8 May 2017 07:48:26 -0000
@@ -1,2 +1,3 @@
-@comment $NetBSD: PLIST,v 1.1 2017/02/17 15:39:38 fhajny Exp $
+@comment $NetBSD$
 bin/pup
+share/doc/pup/README