docs: add redirect dor configuration

Gemfile

@@ -20,6 +20,7 @@ source "https://rubygems.org"
 group :jekyll_plugins do
   gem "jekyll-feed", "~> 0.12"
   gem "jekyll-remote-theme"
+  gem "jekyll-redirect-from"
 end
 
 # Windows and JRuby does not include zoneinfo files, so bundle the tzinfo-data gem

_config.yml

@@ -17,3 +17,6 @@ defaults:
       path: "" # an empty string here means all files in the project
     values:
       image: assets/img/rtfm.png
+
+plugins:
+  - jekyll-redirect-from

configurations/necessary-cfg.md

@@ -4,6 +4,8 @@ title: Configuration
 nav_order: 5
 has_children: false
 permalink: /configuration
+redirect_from:
+  - /necessary-configuration
 ---
 
 # Required configuration