Search Keys 2.1.0

• Unforked, returning to the "Search Keys" name
• Renamed back all references to "Add Search Number"
• Added a "package-lock.json" file for npm 5 usage

Add Search Number 2.0.0

• 2.0.0 (2017-09-13)
  • Finally move off old legacy interfaces, e.g. nsIIOService
  • Make search result link detection use querySelector
  • We no longer focus on elements when they are selected as the focus code was not working well
  • Reinstated/Added support for most major default search engines
    • Yahoo HK/TW/US
    • Bing
    • DuckDuckGo
    • Wikipedia

This has been submitted to Mozilla Add-ons.