update and add atom feed

Gemfile

@@ -6,8 +6,9 @@ gem 'jekyll'
 group :default, :jekyll_plugins do
   gem 'jekyll-scholar', '~> 5.9.1'
   #gem 'jekyll-scholar', :git => '/home/thomas/jekyll-scholar', :branch => 'master'
-  gem 'jekyll-sitemap'
   gem 'jekyll-redirect-from'
+  gem 'jekyll-feed'
+  gem 'jekyll-sitemap'
 end
 
 group :test do

Gemfile.lock

 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (5.0.2)
+    activesupport (5.1.1)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (~> 0.7)
       minitest (~> 5.1)
@@ -26,16 +26,16 @@ GEM
       ffi (>= 1.3.0)
     ffi (1.9.18)
     forwardable-extended (2.6.0)
-    html-proofer (3.6.0)
+    html-proofer (3.7.2)
       activesupport (>= 4.2, < 6.0)
       addressable (~> 2.3)
       colored (~> 1.2)
       mercenary (~> 0.3.2)
-      nokogiri (~> 1.5)
+      nokogiri (~> 1.7)
       parallel (~> 1.3)
       typhoeus (~> 0.7)
       yell (~> 2.0)
-    i18n (0.8.1)
+    i18n (0.8.4)
     jekyll (3.4.3)
       addressable (~> 2.4)
       colorator (~> 1.0)
@@ -47,6 +47,8 @@ GEM
       pathutil (~> 0.9)
       rouge (~> 1.7)
       safe_yaml (~> 1.0)
+    jekyll-feed (0.9.2)
+      jekyll (~> 3.3)
     jekyll-redirect-from (0.12.1)
       jekyll (~> 3.3)
     jekyll-sass-converter (1.5.0)
@@ -56,7 +58,7 @@ GEM
       citeproc-ruby (~> 1.0)
       csl-styles (~> 1.0)
       jekyll (~> 3.0)
-    jekyll-sitemap (1.0.0)
+    jekyll-sitemap (1.1.1)
       jekyll (~> 3.3)
     jekyll-watch (1.5.0)
       listen (~> 3.0, < 3.1)
@@ -68,28 +70,28 @@ GEM
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
     mercenary (0.3.6)
-    mini_portile2 (2.1.0)
-    minitest (5.10.1)
+    mini_portile2 (2.2.0)
+    minitest (5.10.2)
     namae (0.11.3)
-    nokogiri (1.7.1)
-      mini_portile2 (~> 2.1.0)
-    parallel (1.11.1)
+    nokogiri (1.8.0)
+      mini_portile2 (~> 2.2.0)
+    parallel (1.11.2)
     pathutil (0.14.0)
       forwardable-extended (~> 2.6)
     public_suffix (2.0.5)
     rake (12.0.0)
     rb-fsevent (0.9.8)
-    rb-inotify (0.9.8)
-      ffi (>= 0.5.0)
+    rb-inotify (0.9.9)
+      ffi (~> 1.0)
     rouge (1.11.1)
     safe_yaml (1.0.4)
-    sass (3.4.23)
+    sass (3.4.24)
     thread_safe (0.3.6)
     typhoeus (0.8.0)
       ethon (>= 0.8.0)
     tzinfo (1.2.3)
       thread_safe (~> 0.1)
-    unicode (0.4.4.2)
+    unicode (0.4.4.4)
     yell (2.0.7)
 
 PLATFORMS
@@ -98,10 +100,11 @@ PLATFORMS
 DEPENDENCIES
   html-proofer (~> 3.0)
   jekyll
+  jekyll-feed
   jekyll-redirect-from
   jekyll-scholar (~> 5.9.1)
   jekyll-sitemap
   rake
 
 BUNDLED WITH
-   1.14.6
+   1.15.1

_includes/head.html

@@ -14,6 +14,8 @@
   <link rel="stylesheet" href="{{ "/assets/syntax.css" | prepend: site.baseurl }}">
   {% if page.dataspy %}<link rel="stylesheet" href="{{ "/assets/fixed-sticky/fixedsticky.css" | prepend: site.baseurl }}">{% endif %}
 
+  {% feed_meta %}
+
   <script>
     (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
     (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),