移除一些无用插件 (#289)

Gemfile

@@ -15,11 +15,7 @@ group :jekyll_plugins do
   gem "jekyll-sitemap", "1.4.0"
   gem "jekyll-gist", "1.5.0"
   gem "jekyll-feed", "0.17.0"
-  gem "jemoji", "0.13.0"
   gem "jekyll-include-cache", "0.2.1"
-  gem "jekyll-algolia", "1.7.1"
-  gem "jekyll-archives", "2.3.0"
-  gem "jekyll-seo-tag", "2.8.0"
 end
 
 # Windows and JRuby does not include zoneinfo files, so bundle the tzinfo-data gem

_config.yml

@@ -66,9 +66,6 @@ plugins:
   - jekyll-gist
   - jekyll-feed
   - jekyll-include-cache
-  - jemoji
-  - jekyll-archives
-  - jekyll-seo-tag
 # minimal-mistakes (mimic GitHub Pages with --safe)
 # whitelist:
 #   - jekyll-paginate