fix: Security upgrade github-pages from 214 to 215 (#142)

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-RUBY-ADDRESSABLE-1316242

Author: snyk-bot

docs/Gemfile.lock

@@ -1,13 +1,13 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (6.0.3.7)
+    activesupport (6.0.4)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
       zeitwerk (~> 2.2, >= 2.2.2)
-    addressable (2.7.0)
+    addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
     coffee-script (2.4.1)
       coffee-script-source
@@ -16,8 +16,8 @@ GEM
     colorator (1.1.0)
     commonmarker (0.17.13)
       ruby-enum (~> 0.5)
-    concurrent-ruby (1.1.8)
-    dnsruby (1.61.5)
+    concurrent-ruby (1.1.9)
+    dnsruby (1.61.7)
       simpleidn (~> 0.1)
     em-websocket (0.5.2)
       eventmachine (>= 0.12.9)
@@ -27,21 +27,29 @@ GEM
     eventmachine (1.2.7)
     eventmachine (1.2.7-x64-mingw32)
     execjs (2.8.1)
-    faraday (1.4.1)
+    faraday (1.5.0)
+      faraday-em_http (~> 1.0)
+      faraday-em_synchrony (~> 1.0)
       faraday-excon (~> 1.1)
+      faraday-httpclient (~> 1.0.1)
       faraday-net_http (~> 1.0)
       faraday-net_http_persistent (~> 1.1)
+      faraday-patron (~> 1.0)
       multipart-post (>= 1.2, < 3)
       ruby2_keywords (>= 0.0.4)
+    faraday-em_http (1.0.0)
+    faraday-em_synchrony (1.0.0)
     faraday-excon (1.1.0)
+    faraday-httpclient (1.0.1)
     faraday-net_http (1.0.1)
     faraday-net_http_persistent (1.1.0)
-    ffi (1.15.0)
-    ffi (1.15.0-x64-mingw32)
+    faraday-patron (1.0.0)
+    ffi (1.15.3)
+    ffi (1.15.3-x64-mingw32)
     forwardable-extended (2.6.0)
     gemoji (3.0.1)
-    github-pages (214)
-      github-pages-health-check (= 1.17.0)
+    github-pages (215)
+      github-pages-health-check (= 1.17.2)
       jekyll (= 3.9.0)
       jekyll-avatar (= 0.7.0)
       jekyll-coffeescript (= 1.1.1)
@@ -84,7 +92,7 @@ GEM
       nokogiri (>= 1.10.4, < 2.0)
       rouge (= 3.26.0)
       terminal-table (~> 1.4)
-    github-pages-health-check (1.17.0)
+    github-pages-health-check (1.17.2)
       addressable (~> 2.3)
       dnsruby (~> 1.60)
       octokit (~> 4.0)
@@ -211,17 +219,17 @@ GEM
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
-    mini_portile2 (2.5.1)
+    mini_portile2 (2.5.3)
     minima (2.5.1)
       jekyll (>= 3.5, < 5.0)
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
     minitest (5.14.4)
     multipart-post (2.1.1)
-    nokogiri (1.11.4)
+    nokogiri (1.11.7)
       mini_portile2 (~> 2.5.0)
       racc (~> 1.4)
-    nokogiri (1.11.4-x64-mingw32)
+    nokogiri (1.11.7-x64-mingw32)
       racc (~> 1.4)
     octokit (4.21.0)
       faraday (>= 0.9)
@@ -238,7 +246,7 @@ GEM
     ruby-enum (0.9.0)
       i18n
     ruby2_keywords (0.0.4)
-    rubyzip (2.3.0)
+    rubyzip (2.3.2)
     safe_yaml (1.0.5)
     sass (3.7.4)
       sass-listen (~> 4.0.0)
@@ -269,7 +277,7 @@ PLATFORMS
   x64-mingw32
 
 DEPENDENCIES
-  github-pages (>= 209)
+  github-pages (>= 214)
   nokogiri (>= 1.11.4)
 
 BUNDLED WITH