Update GitHub Pages Theme to v0.3.1

Gemfile

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
+
+# gem "rails"
+
+gem "jekyll", "~> 3.8"
+gem "github-pages"

_config.yml

@@ -12,12 +12,16 @@ exclude:
   - "bin/"
   - "src/"
   - "tests/"
+  - "vendor/"
   - "Gemfile"
   - "*.json"
   - "*.lock"
 
 plugins:
   - github-pages
+  - jekyll-github-metadata
+  - jekyll-remote-theme
+  - jekyll-seo-tag
 
 # Extend the Docs settings (see https://pother.ca/extend-the-docs/)
 nav:
@@ -35,11 +39,11 @@ nav:
     link: '/'
   recurse: true
 
-  # Just the Docs settings (see https://pmarsceill.github.io/just-the-docs/docs/configuration/)
+# Just the Docs settings (see https://pmarsceill.github.io/just-the-docs/docs/configuration/)
 aux_links:
   "PDS Interop on GitHub":
     - https://github.com/pdsinterop
-footer_content: Copyright © 2020 PDS Interop. Distributed under a <a href="https://pdsinterop.org/license/">MIT license.</a>
+footer_content: '<p xmlns:dct="http://purl.org/dc/terms/" property="dct:rights">Copyright © <span property="dct:dateCopyrighted">2020-2021</span> <span property="dct:publisher">PDS Interop</span>. Distributed under a <a rel="license" href="https://pdsinterop.org/license/">MIT license</a>.</p>'
 gh_edit_link: true
 gh_edit_repository: https://github.com/pdsinterop/flysystem-nextcloud
 logo: https://avatars3.githubusercontent.com/u/65920341