Remove unneccesary code in definition.rb, improve docs, and update naming for callback module

Author: Aryan Soni

lib/ruby_lsp/ruby_lsp_rails/definition.rb

@@ -10,22 +10,16 @@ module Rails
     # definition of the symbol under the cursor.
     #
     # Currently supported targets:
-    # - Classes
-    # - Modules
-    # - Constants
-    # - Require paths
-    # - Methods invoked on self only
+    # - Callbacks
     #
     # # Example
     #
     # ```ruby
-    # require "some_gem/file" # <- Request go to definition on this string will take you to the file
-    # Product.new # <- Request go to definition on this class name will take you to its declaration.
+    # before_action :foo # <- Request go to definition on this symbol will take you to the method
     # ```
     class Definition
       extend T::Sig
       include Requests::Support::Common
-      include ActiveSupportTestCaseHelper
       include Support::Callbacks
 
       sig do

misc/definition.gif

@@ -8,11 +8,6 @@ module Rails
     class DefinitionTest < ActiveSupport::TestCase
       setup do
         @message_queue = Thread::Queue.new
-
-        # Build the Rails documents index ahead of time
-        capture_io do
-          Support::RailsDocumentClient.send(:search_index)
-        end
       end
 
       def teardown