Add rails-erd gem

Only in development environment.

Gemfile

@@ -169,6 +169,7 @@ end
 
 group :development do
   gem 'debugger-linecache'
+  gem 'rails-erd'
   gem 'foreman'
   gem 'listen'
   gem 'pry', '~> 0.13.0'

Gemfile.lock

@@ -203,6 +203,7 @@ GEM
       marcel (~> 1.0)
       nokogiri (~> 1.10, >= 1.10.4)
       rubyzip (>= 1.3.0, < 3)
+    choice (0.2.0)
     chronic (0.10.2)
     cliver (0.3.2)
     coderay (1.1.3)
@@ -471,6 +472,11 @@ GEM
     rails-dom-testing (2.0.3)
       activesupport (>= 4.2.0)
       nokogiri (>= 1.6)
+    rails-erd (1.7.2)
+      activerecord (>= 4.2)
+      activesupport (>= 4.2)
+      choice (~> 0.2.0)
+      ruby-graphviz (~> 1.2)
     rails-html-sanitizer (1.4.3)
       loofah (~> 2.3)
     rails-i18n (7.0.5)
@@ -564,6 +570,8 @@ GEM
       activesupport (>= 4.2.0)
       rack (>= 1.1)
       rubocop (>= 1.33.0, < 2.0)
+    ruby-graphviz (1.2.5)
+      rexml
     ruby-progressbar (1.11.0)
     ruby-rc4 (0.1.5)
     ruby-vips (2.1.4)
@@ -765,6 +773,7 @@ DEPENDENCIES
   rack-timeout
   rails (>= 6.1.4)
   rails-controller-testing
+  rails-erd
   rails-i18n
   rails_safe_tasks (~> 1.0)
   ransack (= 2.4.2)