* fix: backport patch to fix systemd unit activation in Chromium
This backports a patch from Chromium, which fixes systemd unit
activation. That is, a globalShortcuts feature that Chromium has
needs to create a systemd unit and rename it properly. Portal's
global shortcuts uses that name afterwards to map the app with
the shortcuts bound. However, there might be a race between
Chromium binding shortcuts and renaming the unit.
This is a first step to add Portal's globalShortcuts to
Electron.
* feat: Support global shortcuts via GlobalShortcutsPortal feature
Chromium has a new feature called GlobalShortcutsPortal. It
allows clients to use Portal's globalShortcuts to register and
listen to shortcuts.
This patches adds necessary bits, which allows Electron to
use that feature.
In order to make it work, one has to add
--enable-features=GlobalShortcutsPortal
Test: tested manually with a sample app.
* docs: add GlobalShortcutsPortal feature to globalShortcuts docs
Electron supports Portal's globalShortcuts API now via Chromium, and Electron
apps can use that in a Wayland session. Update the docs with the required
feature flag that must be passed to be able to use that implementation.
* docs: add references to app.whenReady() in isReady
* refactor: prefer app.whenReady()
In the docs, specs, and lib, replace instances of `app.once('ready')`
(seen occasionally) and `app.on('ready')` (extremely common) with
`app.whenReady()`.
It's better to encourage users to use whenReady():
1. it handles the edge case of registering for 'ready' after it's fired
2. it avoids the minor wart of leaving an active listener alive for
an event that wll never fire again
* Change `var` to `let`.
* Change `function() {}` to `() => {}`.
* Use shorthand function syntax on object notation.
* Remove spaces between object notation brackets.
* Small fixes.
