py-pygfm - Note dependency on py-markdown<3.0.0 and add HOMEPAGE

py-pygfm has a hard requirement of py-markdown before 3.0.0 for now,
so it's worth noting that in the Makefile. While there, add a link
to the homepage which is just its github page.

--Kurt

Index: Makefile
===================================================================
RCS file: /cvs/ports/textproc/py-pygfm/Makefile,v
retrieving revision 1.2
diff -u -p -r1.2 Makefile
--- Makefile 21 Oct 2018 12:09:04 -0000 1.2
+++ Makefile 27 Feb 2019 13:57:08 -0000
@@ -8,6 +8,8 @@ PKGNAME = py-${DISTNAME:S/py-/py/}

CATEGORIES = textproc

+HOMEPAGE = https://github.com/zopieux/py-gfm
+
MAINTAINER = Jasper Lievisse Adriaanse <jasper@openbsd.org>

# MIT
@@ -21,6 +23,7 @@ MODPY_SETUPTOOLS = Yes
FLAVORS = python3
FLAVOR ?=

-RUN_DEPENDS = textproc/py-markdown${MODPY_FLAVOR}
+# For now py-pygfm is not compatible with py-markdown>=3.0.0
+RUN_DEPENDS = textproc/py-markdown${MODPY_FLAVOR}<3.0.0

.include <bsd.port.mk>