Bump github-pages from 217 to 220 in /docs (#1070)

Bumps [github-pages](https://github.com/github/pages-gem) from 217 to 220.
- [Release notes](https://github.com/github/pages-gem/releases)
- [Commits](https://github.com/github/pages-gem/compare/v217...v220)

---
updated-dependencies:
- dependency-name: github-pages
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

docs/Gemfile.lock

@@ -6,8 +6,8 @@ GEM
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
-    addressable (2.8.0)
+    addressable (2.8.6)
-      public_suffix (>= 2.0.2, < 5.0)
+      public_suffix (>= 2.0.2, < 6.0)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
@@ -16,39 +16,43 @@ GEM
     commonmarker (0.17.13)
       ruby-enum (~> 0.5)
     concurrent-ruby (1.3.1)
-    dnsruby (1.61.7)
+    dnsruby (1.72.1)
-      simpleidn (~> 0.1)
+      simpleidn (~> 0.2.1)
     em-websocket (0.5.3)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0)
-    ethon (0.15.0)
+    ethon (0.16.0)
       ffi (>= 1.15.0)
     eventmachine (1.2.7)
-    execjs (2.7.0)
+    execjs (2.9.0)
-    faraday (1.8.0)
+    faraday (1.10.3)
       faraday-em_http (~> 1.0)
       faraday-em_synchrony (~> 1.0)
       faraday-excon (~> 1.1)
-      faraday-httpclient (~> 1.0.1)
+      faraday-httpclient (~> 1.0)
+      faraday-multipart (~> 1.0)
       faraday-net_http (~> 1.0)
-      faraday-net_http_persistent (~> 1.1)
+      faraday-net_http_persistent (~> 1.0)
       faraday-patron (~> 1.0)
       faraday-rack (~> 1.0)
-      multipart-post (>= 1.2, < 3)
+      faraday-retry (~> 1.0)
       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-multipart (1.0.4)
+      multipart-post (~> 2)
     faraday-net_http (1.0.1)
     faraday-net_http_persistent (1.2.0)
     faraday-patron (1.0.0)
     faraday-rack (1.0.0)
-    ffi (1.15.4)
+    faraday-retry (1.0.3)
+    ffi (1.15.5)
     forwardable-extended (2.6.0)
-    gemoji (3.0.0)
+    gemoji (3.0.1)
-    github-pages (217)
+    github-pages (220)
-      github-pages-health-check (= 1.17.2)
+      github-pages-health-check (= 1.17.9)
       jekyll (= 3.9.0)
       jekyll-avatar (= 0.7.0)
       jekyll-coffeescript (= 1.1.1)
@@ -67,6 +71,20 @@ GEM
       jekyll-sass-converter (= 1.5.2)
       jekyll-seo-tag (= 2.7.1)
       jekyll-sitemap (= 1.4.0)
+      jekyll-swiss (= 1.0.0)
+      jekyll-theme-architect (= 0.2.0)
+      jekyll-theme-cayman (= 0.2.0)
+      jekyll-theme-dinky (= 0.2.0)
+      jekyll-theme-hacker (= 0.2.0)
+      jekyll-theme-leap-day (= 0.2.0)
+      jekyll-theme-merlot (= 0.2.0)
+      jekyll-theme-midnight (= 0.2.0)
+      jekyll-theme-minimal (= 0.2.0)
+      jekyll-theme-modernist (= 0.2.0)
+      jekyll-theme-primer (= 0.6.0)
+      jekyll-theme-slate (= 0.2.0)
+      jekyll-theme-tactile (= 0.2.0)
+      jekyll-theme-time-machine (= 0.2.0)
       jekyll-titles-from-headings (= 0.5.3)
       jemoji (= 0.12.0)
       kramdown (= 2.3.1)
@@ -77,13 +95,13 @@ GEM
       nokogiri (>= 1.10.4, < 2.0)
       rouge (= 3.26.0)
       terminal-table (~> 1.4)
-    github-pages-health-check (1.17.2)
+    github-pages-health-check (1.17.9)
       addressable (~> 2.3)
       dnsruby (~> 1.60)
       octokit (~> 4.0)
-      public_suffix (>= 2.0.2, < 5.0)
+      public_suffix (>= 3.0, < 5.0)
       typhoeus (~> 1.3)
-    html-pipeline (2.10.0)
+    html-pipeline (2.14.3)
       activesupport (>= 2)
       nokogiri (>= 1.4)
     http_parser.rb (0.8.0)
@@ -107,9 +125,9 @@ GEM
     jekyll-coffeescript (1.1.1)
       coffee-script (~> 2.2)
       coffee-script-source (~> 1.11.1)
-    jekyll-commonmark (1.2.0)
+    jekyll-commonmark (1.3.1)
       commonmarker (~> 0.14)
-      jekyll (>= 3.0, < 4.0)
+      jekyll (>= 3.7, < 5.0)
     jekyll-commonmark-ghpages (0.1.6)
       commonmarker (~> 0.17.6)
       jekyll-commonmark (~> 1.2)
@@ -146,6 +164,47 @@ GEM
       jekyll (>= 3.8, < 5.0)
     jekyll-sitemap (1.4.0)
       jekyll (>= 3.7, < 5.0)
+    jekyll-swiss (1.0.0)
+    jekyll-theme-architect (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-cayman (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-dinky (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-hacker (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-leap-day (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-merlot (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-midnight (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-minimal (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-modernist (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-primer (0.6.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-github-metadata (~> 2.9)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-slate (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-tactile (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
+    jekyll-theme-time-machine (0.2.0)
+      jekyll (> 3.5, < 5.0)
+      jekyll-seo-tag (~> 2.0)
     jekyll-titles-from-headings (0.5.3)
       jekyll (>= 3.3, < 5.0)
     jekyll-watch (2.2.1)
@@ -159,60 +218,52 @@ GEM
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
     liquid (4.0.3)
-    listen (3.1.5)
+    listen (3.9.0)
-      rb-fsevent (~> 0.9, >= 0.9.4)
+      rb-fsevent (~> 0.10, >= 0.10.3)
-      rb-inotify (~> 0.9, >= 0.9.7)
+      rb-inotify (~> 0.9, >= 0.9.10)
-      ruby_dep (~> 1.2)
     mercenary (0.3.6)
-    mini_portile2 (2.8.5)
+    mini_portile2 (2.4.0)
     minima (2.5.1)
       jekyll (>= 3.5, < 5.0)
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
     minitest (5.15.0)
-    multipart-post (2.1.1)
+    multipart-post (2.3.0)
-    nokogiri (1.15.5)
+    nokogiri (1.10.10)
-      mini_portile2 (~> 2.8.2)
+      mini_portile2 (~> 2.4.0)
-      racc (~> 1.4)
+    octokit (4.25.1)
-    octokit (4.21.0)
+      faraday (>= 1, < 3)
-      faraday (>= 0.9)
+      sawyer (~> 0.9)
-      sawyer (~> 0.8.0, >= 0.5.3)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    public_suffix (3.1.1)
+    public_suffix (4.0.7)
-    racc (1.7.3)
+    rb-fsevent (0.11.2)
-    rb-fsevent (0.11.0)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     rexml (3.2.5)
     rouge (3.26.0)
-    ruby-enum (0.7.2)
+    ruby-enum (0.9.0)
       i18n
     ruby2_keywords (0.0.5)
-    ruby_dep (1.5.0)
+    rubyzip (2.3.2)
-    rubyzip (2.1.0)
     safe_yaml (1.0.5)
     sass (3.7.4)
       sass-listen (~> 4.0.0)
     sass-listen (4.0.0)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
-    sawyer (0.8.2)
+    sawyer (0.9.2)
       addressable (>= 2.3.5)
-      faraday (> 0.8, < 2.0)
+      faraday (>= 0.17.3, < 3)
-    simpleidn (0.2.1)
+    simpleidn (0.2.3)
-      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)
+    typhoeus (1.4.1)
       ethon (>= 0.9.0)
     tzinfo (1.2.11)
       thread_safe (~> 0.1)
-    unf (0.1.4)
+    unicode-display_width (1.8.0)
-      unf_ext
-    unf_ext (0.0.8)
-    unicode-display_width (1.5.0)
 
 PLATFORMS
   ruby