Update Git documentation (2.31.0)

assets/javascripts/templates/pages/about_tmpl.coffee

@@ -318,7 +318,7 @@ credits = [
     'https://www.gnu.org/licenses/fdl-1.3.en.html'
   ], [
     'Git',
-    '2012-2018 Scott Chacon and others',
+    '2012-2021 Scott Chacon and others',
     'MIT',
     'https://raw.githubusercontent.com/git/git-scm.com/master/MIT-LICENSE.txt'
   ], [

lib/docs/scrapers/git.rb

@@ -1,7 +1,7 @@
 module Docs
   class Git < UrlScraper
     self.type = 'git'
-    self.release = '2.30.0'
+    self.release = '2.31.0'
     self.base_url = 'https://git-scm.com/docs'
     self.initial_paths = %w(/git.html)
     self.links = {
@@ -16,7 +16,7 @@ module Docs
     options[:skip] = %w(/howto-index.html)
 
     options[:attribution] = <<-HTML
-      &copy; 2012&ndash;2018 Scott Chacon and others<br>
+      &copy; 2012&ndash;2021 Scott Chacon and others<br>
       Licensed under the MIT License.
     HTML