Add .desktop file and a script to regenerate it

build/irccloud.desktop

@@ -0,0 +1,10 @@
+[Desktop Entry]
+Name=IRCCloud
+Exec=/opt/IRCCloud/irccloud --no-sandbox %U
+Terminal=false
+Type=Application
+Icon=irccloud
+StartupWMClass=IRCCloud
+Comment=IRCCloud Desktop Client
+MimeType=x-scheme-handler/irc;x-scheme-handler/ircs;
+Categories=Network;IRCClient;

package.json

@@ -35,7 +35,8 @@
     "snyk": "snyk test",
     "test": "eslint app",
     "snyk-protect": "snyk protect",
-    "prepare": "yarn run snyk-protect"
+    "prepare": "yarn run snyk-protect",
+    "desktop-file": "node ./scripts/desktop-file.js"
   },
   "irccloud": {},
   "devDependencies": {

scripts/desktop-file.js

@@ -0,0 +1,13 @@
+const b = require('electron-builder');
+const LinuxTargetHelper = require("app-builder-lib/out/targets/LinuxTargetHelper");
+
+const config = require('../electron-builder.json');
+const pkg = require('../package.json');
+
+let p = new b.Packager({linux: ['deb']});
+p._configuration = config;
+p._metadata = pkg;
+
+let h = p.createHelper(b.Platform.LINUX);
+let lth = new LinuxTargetHelper.LinuxTargetHelper(h);
+lth.writeDesktopEntry(config.linux, null, `./build/${config.linux.executableName}.desktop`);