redirect old contributing page to new location

Gemfile

@@ -20,6 +20,7 @@ group :jekyll_plugins do
   gem 'jekyll-sitemap'
   gem 'jekyll-seo-tag'
   gem 'jekyll-paginate'
+  gem 'jekyll-redirect-from'
 end
 
 group :development do

Gemfile.lock

@@ -35,6 +35,8 @@ GEM
       deep_merge (~> 1.2)
       jekyll (~> 3.0)
     jekyll-paginate (1.1.0)
+    jekyll-redirect-from (0.15.0)
+      jekyll (>= 3.3, < 5.0)
     jekyll-sass-converter (1.5.2)
       sass (~> 3.4)
     jekyll-seo-tag (2.5.0)
@@ -77,6 +79,7 @@ DEPENDENCIES
   jekyll (~> 3.8.4)
   jekyll-get-json (~> 0.0.1)
   jekyll-paginate
+  jekyll-redirect-from
   jekyll-seo-tag
   jekyll-sitemap
   rake

_config.yml

@@ -13,6 +13,7 @@ plugins:
   - jekyll-seo-tag
   - jekyll-paginate
   - jekyll-get-json
+  - jekyll-redirect-from
 # Build settings
 markdown: kramdown
 kramdown:

libraries/contributing/index.html

@@ -0,0 +1,13 @@
+---
+layout: default
+title: Libraries
+permalink: /libraries/contributing
+redirect_to: /contributing
+---
+<div id="libraries-page" class="common-layout">
+  <div class="content">
+    <p>This page has moved to <a href="/contributing">the dedicated contributing
+      page</a>.
+    </p>
+  </div>
+</div>