Added redirect for downgrade docs

Author: vikram-redhat

.gitignore

@@ -3,7 +3,7 @@ Gemfile.lock
 .asciidoctor
 _package
 _preview
-drupal-builds
+drupal-build
 architecture/core_concepts/images/docker-diagram.png
 architecture/core_concepts/images/docker-diagram.png.cache
 dev_guide/builds/images/chained-build.png

.s2i/httpd-cfg/01-commercial.conf

@@ -205,6 +205,7 @@ AddType text/vtt                            vtt
     RewriteRule ^(container-platform|enterprise)/(3\.1|3\.2|3\.3|3\.4|3\.5|3\.6)/install_config/upgrades\.html(.*)$ /$1/$2/install_config/upgrading/index.html$3 [NE,R=301]
     RewriteRule ^container-platform/(3\.7)/install_config/upgrades\.html(.*)$ /container-platform/$1/upgrading/index.html$2 [NE,R=301]
     RewriteRule ^container-platform/(3\.7)/install_config/upgrading/(.*)$ /container-platform/$1/upgrading/$2 [NE,R=301]
+    RewriteRule ^container-platform/(3\.7)/install_config/downgrade\.html /container-platform/3\.7/upgrading/downgrade.html [NE,R=301]
 
   </Directory>
 </IfModule>