Add default label and accelerator for menu item roles

[kevinsawicki]

Adds fallback labels and accelerators for all MenuItem roles.

This allows you to use menu item roles like so:

{
      label: 'Edit',
      submenu: [
        {
          role: 'undo'
        },
        {
          role: 'redo'
        },
        {
          type: 'separator'
        },
        {
          role: 'cut'
        },
        {
          role: 'copy'
        },
        {
          role: 'paste'
        }
}

And the accelerators and labels will be automatically provided as so:

Close #2812

[kevinsawicki]

/cc @sindresorhus 👀

[sindresorhus]

Awesome!

One of the main benefits of doing this would have been automatic localization. Doesn't look like this PR handles that. From the issue:

we can probably copy and use the resources from Chromium.

[kevinsawicki]

One of the main benefits of doing this would have been automatic localization. Doesn't look like this PR handles that.

Nope, that will be handled in a subsequent up pull request. 🌎

[sindresorhus]

Should be:

process.platform === 'linux' ? 'About' : `About ${appName}`

On Linux, they don't include the app name.

[sindresorhus]

// @danhp

[kevinsawicki]

@sindresorhus thanks for the review, I've incorporated your feedback 👍

[sindresorhus]

LGTM

[danhp]

Ctrl -> Control

[danhp]

Aside from the tiny nitpick, it looks good.

[zcbenz]

👍