Add glossary entries to search results page

[zeke]

If a given search term exists in the Electron glossary for the user's current locale, it should be displayed at the top of the page:

require('./lib/i18n').glossary['en-US'].IPC

{
  term: 'IPC',
  description: 'IPC stands for Inter-Process Communication. Electron uses IPC to send serialized JSON messages between the main and renderer processes.' 
}

Kind of like when Google shows a dictionary entry above the search results:

[zeke]

The first step to making this happen would be creating an Algolia search index for the glossary entries: https://github.com/electron/algolia-indices/issues/22