main/menu.js: minor refactor

Just some code cleanup to make menu.js more internally consistent.

- Name the electron.dialog returned value `selectedPaths` which is more
accurate.

- Move the file menu into the `template` object, like the rest of the
menus. Then reach in afterwards for OS-specific tweaks.

config.js

@@ -28,8 +28,11 @@ module.exports = {
   CONFIG_TORRENT_PATH: path.join(getConfigPath(), 'Torrents'),
 
   GITHUB_URL: 'https://github.com/feross/webtorrent-desktop',
+  GITHUB_URL_ISSUES: 'https://github.com/feross/webtorrent-desktop/issues',
   GITHUB_URL_RAW: 'https://raw.githubusercontent.com/feross/webtorrent-desktop/master',
 
+  HOME_PAGE_URL: 'https://webtorrent.io',
+
   IS_PORTABLE: isPortable(),
   IS_PRODUCTION: isProduction(),