Bump github-pages from 209 to 212 in /docs (#11)

Bumps [github-pages](https://github.com/github/pages-gem) from 209 to 212.
- [Release notes](https://github.com/github/pages-gem/releases)
- [Commits](github/pages-gem@v209...v212)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

docs/Gemfile.lock

@@ -1,7 +1,7 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (6.0.3.4)
+    activesupport (6.0.3.5)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
@@ -16,7 +16,7 @@ GEM
     colorator (1.1.0)
     commonmarker (0.17.13)
       ruby-enum (~> 0.5)
-    concurrent-ruby (1.1.7)
+    concurrent-ruby (1.1.8)
     dnsruby (1.61.5)
       simpleidn (~> 0.1)
     em-websocket (0.5.2)
@@ -26,14 +26,16 @@ GEM
       ffi (>= 1.3.0)
     eventmachine (1.2.7)
     execjs (2.7.0)
-    faraday (1.1.0)
+    faraday (1.3.0)
+      faraday-net_http (~> 1.0)
       multipart-post (>= 1.2, < 3)
       ruby2_keywords
-    ffi (1.13.1)
+    faraday-net_http (1.0.1)
+    ffi (1.14.2)
     forwardable-extended (2.6.0)
     gemoji (3.0.1)
-    github-pages (209)
-      github-pages-health-check (= 1.16.1)
+    github-pages (212)
+      github-pages-health-check (= 1.17.0)
       jekyll (= 3.9.0)
       jekyll-avatar (= 0.7.0)
       jekyll-coffeescript (= 1.1.1)
@@ -50,7 +52,7 @@ GEM
       jekyll-relative-links (= 0.6.1)
       jekyll-remote-theme (= 0.4.2)
       jekyll-sass-converter (= 1.5.2)
-      jekyll-seo-tag (= 2.6.1)
+      jekyll-seo-tag (= 2.7.1)
       jekyll-sitemap (= 1.4.0)
       jekyll-swiss (= 1.0.0)
       jekyll-theme-architect (= 0.1.1)
@@ -74,13 +76,13 @@ GEM
       mercenary (~> 0.3)
       minima (= 2.5.1)
       nokogiri (>= 1.10.4, < 2.0)
-      rouge (= 3.23.0)
+      rouge (= 3.26.0)
       terminal-table (~> 1.4)
-    github-pages-health-check (1.16.1)
+    github-pages-health-check (1.17.0)
       addressable (~> 2.3)
       dnsruby (~> 1.60)
       octokit (~> 4.0)
-      public_suffix (~> 3.0)
+      public_suffix (>= 2.0.2, < 5.0)
       typhoeus (~> 1.3)
     html-pipeline (2.14.0)
       activesupport (>= 2)
@@ -141,8 +143,8 @@ GEM
       rubyzip (>= 1.3.0, < 3.0)
     jekyll-sass-converter (1.5.2)
       sass (~> 3.4)
-    jekyll-seo-tag (2.6.1)
-      jekyll (>= 3.3, < 5.0)
+    jekyll-seo-tag (2.7.1)
+      jekyll (>= 3.8, < 5.0)
     jekyll-sitemap (1.4.0)
       jekyll (>= 3.7, < 5.0)
     jekyll-swiss (1.0.0)
@@ -199,33 +201,35 @@ GEM
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
     liquid (4.0.3)
-    listen (3.3.3)
+    listen (3.4.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
-    mini_portile2 (2.4.0)
+    mini_portile2 (2.5.0)
     minima (2.5.1)
       jekyll (>= 3.5, < 5.0)
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
-    minitest (5.14.2)
+    minitest (5.14.3)
     multipart-post (2.1.1)
-    nokogiri (1.10.10)
-      mini_portile2 (~> 2.4.0)
-    octokit (4.19.0)
+    nokogiri (1.11.1)
+      mini_portile2 (~> 2.5.0)
+      racc (~> 1.4)
+    octokit (4.20.0)
       faraday (>= 0.9)
       sawyer (~> 0.8.0, >= 0.5.3)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    public_suffix (3.1.1)
+    public_suffix (4.0.6)
+    racc (1.5.2)
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     rexml (3.2.4)
-    rouge (3.23.0)
-    ruby-enum (0.8.0)
+    rouge (3.26.0)
+    ruby-enum (0.9.0)
       i18n
-    ruby2_keywords (0.0.2)
+    ruby2_keywords (0.0.4)
     rubyzip (2.3.0)
     safe_yaml (1.0.5)
     sass (3.7.4)
@@ -236,14 +240,14 @@ GEM
     sawyer (0.8.2)
       addressable (>= 2.3.5)
       faraday (> 0.8, < 2.0)
-    simpleidn (0.1.1)
+    simpleidn (0.2.1)
       unf (~> 0.1.4)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
     thread_safe (0.3.6)
     typhoeus (1.4.0)
       ethon (>= 0.9.0)
-    tzinfo (1.2.8)
+    tzinfo (1.2.9)
       thread_safe (~> 0.1)
     unf (0.1.4)
       unf_ext