Add sitemap and robots.txt for better index on Web

Author: yasulab

Gemfile

@@ -3,3 +3,11 @@ source "https://rubygems.org"
 git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 
 gem 'jekyll'
+
+group :jekyll_plugins do
+  gem 'jekyll-sitemap'
+
+  # No need this gem because we build by GitHub Actions and
+  # serve the built results (static files) on GitHub Pages.
+  # gem 'github-pages'
+end

Gemfile.lock

@@ -12,6 +12,7 @@ GEM
     ffi (1.15.5)
     forwardable-extended (2.6.0)
     google-protobuf (3.21.12)
+    google-protobuf (3.21.12-x86_64-linux)
     http_parser.rb (0.8.0)
     i18n (1.12.0)
       concurrent-ruby (~> 1.0)
@@ -33,6 +34,8 @@ GEM
       webrick (~> 1.7)
     jekyll-sass-converter (3.0.0)
       sass-embedded (~> 1.54)
+    jekyll-sitemap (1.4.0)
+      jekyll (>= 3.7, < 5.0)
     jekyll-watch (2.2.1)
       listen (~> 3.0)
     kramdown (2.4.0)
@@ -68,6 +71,7 @@ PLATFORMS
 
 DEPENDENCIES
   jekyll
+  jekyll-sitemap
 
 BUNDLED WITH
-   2.4.1
+   2.3.26

_config.yml

@@ -2,6 +2,10 @@
 url:     "https://map.coderdojo.jp"
 baseurl: "/" # the subpath of your site, e.g. /blog
 
+# Build settings
+plugins:
+  - jekyll-sitemap # This must be LAST to include contents generated by gems above
+
 exclude:
   - README.md
   - LICENSE.md

robots.txt

@@ -0,0 +1,7 @@
+# See http://www.robotstxt.org/robotstxt.html for documentation on how to use the robots.txt file
+#
+# To ban all spiders from the entire site uncomment the next two lines:
+User-agent: *
+Allow: /
+
+Sitemap: https://map.coderdojo.jp/sitemap.xml