Merge branch 'seo' into 'master'

Added SEO plugin stuffs like the website said.

See merge request !27

_config.yml

@@ -25,6 +25,7 @@ defaults:
 gems:
   - jekyll-paginate
   - jekyll-feed
+  - jekyll-seo-tag
 
 # Custom variables
 version: "1.1.0"
@@ -34,3 +35,6 @@ excerpt_separator: <!--more-->
 custom_header: false
 custom_nav_footer: false
 reverse: false
+
+twitter:
+  username: monero
\ No newline at end of file

_includes/head.html

@@ -29,5 +29,5 @@
 
 	<!-- RSS -->
 	<link href="/atom.xml" type="application/atom+xml" rel="alternate" title="ATOM Feed" />
-
+{% seo %}
 </head>

_posts/2019-06-27-issue-14.md

 ---
 title: Issue 14: June 20-27, 2019
-img: "/img/twitter-card-issue-14.jpg"
+image: /img/twitter-card-issue-14.jpg
 ---
 [<img src="/img/img-issue14.jpg" alt="Revuo Monero Weekly #14 Slide" class="img-lead">]({% post_url 2019-06-27-issue-14 %}.html)