build: homepage for the deb package

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>

package.json

@@ -4,6 +4,7 @@
   "desktopName": "ink.desktop",
   "version": "1.0.0-beta",
   "description": "A calm, offline Markdown notes app.",
+  "homepage": "https://git.sheol.cc/heaven/ink-note-app",
   "private": true,
   "type": "module",
   "main": "electron/main.cjs",