Add Algolia search provider (#1531)

* Support Lunr and Algolia search providers
* Document search providers and configuration
* Update CHANGELOG and history

close #1416

test/Gemfile

@@ -3,4 +3,8 @@ source "https://rubygems.org"
 # use local theme gem for testing
 gem "minimal-mistakes-jekyll", path: "../"
 
+group :jekyll_plugins do
+  gem 'jekyll-algolia', '~> 1.0'
+end
+
 gem "wdm", "~> 0.1.0" if Gem.win_platform?

test/_config.yml

@@ -51,6 +51,12 @@ atom_feed:
   path                   : # blank (default) uses feed.xml
 search                   : true # true, false (default)
 search_full_content      : true # true, false (default)
+search_provider          : "algolia"
+algolia:
+  application_id         : "QB6HVGBSBA"
+  index_name             : "dev_minimal-mistakes"
+  search_only_api_key    : "9d5014e5bbc77372547bce778dfa5663"
+  powered_by             : true
 
 # SEO Related
 google_site_verification :

test/_pages/search.md

@@ -0,0 +1,5 @@
+---
+title: Search
+layout: search
+permalink: /search/
+---