Added Context menu

[palmtreefrb]

Ubuntu 18.04
Don't know if your are interested, but I wanted the ability to copy/paste from context menu. It was very trivial to add using "electron-context-menu": "^2.2.0" npm package and adding the below code to electron.ts

import * as contextMenu from 'electron-context-menu'

contextMenu({
  prepend: (defaultActions, params, browserWindow) => [
    {
      label: 'Rainbow',
      // Only show it when right-clicking images
      visible: params.mediaType === 'image',
    },
    {
      label: 'Search Google for “{selection}”',
      // Only show it when right-clicking text
      visible: params.selectionText.trim().length > 0,
      click: () => {
        shell.openExternal(`https://google.com/search?q=${encodeURIComponent(params.selectionText)}`)
      },
    },
  ],
})

[thomasnordquist]

Seems to make a nice addition!
The google search is maybe a bit over the top 😅

[palmtreefrb]

Hah, yes, that was just POC.