[Docs] Add TargetRailsVersion to config documentation

Author: koic

README.md

@@ -63,6 +63,26 @@ RuboCop::RakeTask.new do |task|
 end
 ```
 
+## RuboCop Rails configuration
+
+The following settings specific to RuboCop Rails can be configured in `.rubocop.yml`.
+
+### `AllCops: TargetRailsVersion`
+
+What version of Rails is the inspected code using? If a value is specified
+for `TargetRailsVersion` then it is used. Acceptable values are specified
+as a float (e.g., 7.2); the patch version of Rails should not be included.
+
+```yaml
+AllCops:
+  TargetRailsVersion: 7.2
+```
+
+If `TargetRailsVersion` is not set, RuboCop will parse the Gemfile.lock or
+gems.locked file to find the version of Rails that has been bound to the
+application. If neither of those files exist, RuboCop will use Rails 5.0
+as the default.
+
 ## Rails configuration tip
 
 In Rails 6.1+, add the following `config.generators.after_generate` setting to

config/default.yml

@@ -17,12 +17,12 @@ AllCops:
   # Enable checking Active Support extensions.
   # See: https://docs.rubocop.org/rubocop/configuration.html#enable-checking-active-support-extensions
   ActiveSupportExtensionsEnabled: true
-  # What version of Rails is the inspected code using?  If a value is specified
-  # for TargetRailsVersion then it is used.  Acceptable values are specified
-  # as a float (i.e. 5.1); the patch version of Rails should not be included.
-  # If TargetRailsVersion is not set, RuboCop will parse the Gemfile.lock or
+  # What version of Rails is the inspected code using? If a value is specified
+  # for `TargetRailsVersion` then it is used. Acceptable values are specified
+  # as a float (e.g., 7.2); the patch version of Rails should not be included.
+  # If `TargetRailsVersion` is not set, RuboCop will parse the Gemfile.lock or
   # gems.locked file to find the version of Rails that has been bound to the
-  # application.  If neither of those files exist, RuboCop will use Rails 5.0
+  # application. If neither of those files exist, RuboCop will use Rails 5.0
   # as the default.
   TargetRailsVersion: ~
 

docs/modules/ROOT/pages/usage.adoc

@@ -31,6 +31,27 @@ RuboCop::RakeTask.new do |task|
 end
 ----
 
+== RuboCop Rails configuration
+
+The following settings specific to RuboCop Rails can be configured in `.rubocop.yml`.
+
+=== `AllCops: TargetRailsVersion`
+
+What version of Rails is the inspected code using? If a value is specified
+for `TargetRailsVersion` then it is used. Acceptable values are specified
+as a float (e.g., 7.2); the patch version of Rails should not be included.
+
+[source,yaml]
+----
+AllCops:
+  TargetRailsVersion: 7.2
+----
+
+If `TargetRailsVersion` is not set, RuboCop will parse the Gemfile.lock or
+gems.locked file to find the version of Rails that has been bound to the
+application. If neither of those files exist, RuboCop will use Rails 5.0
+as the default.
+
 == Rails configuration tip
 
 In Rails 6.1+, add the following `config.generators.after_generate` setting to