Repair HOMEPAGE url to add the missing "https://".

ok?

Index: Makefile
===================================================================
RCS file: /cvs/ports/textproc/slides/Makefile,v
diff -u -p -u -r1.1.1.1 Makefile
--- Makefile	16 Apr 2024 22:43:06 -0000	1.1.1.1
+++ Makefile	20 May 2025 03:14:28 -0000
@@ -3,9 +3,10 @@ COMMENT =	terminal based presentation to
 MODGO_MODNAME =	github.com/maaslalani/slides
 MODGO_VERSION = v0.9.0
 DISTNAME =	slides-${MODGO_VERSION}
+REVISION =	0
 
 CATEGORIES =	textproc productivity
-HOMEPAGE =	github.com/maaslalani/slides
+HOMEPAGE =	https://github.com/maaslalani/slides
 
 MAINTAINER =	Edd Barrett <edd@openbsd.org>