Add subgroups for the provided features

Author: paulbalandan

README.md

@@ -9,8 +9,13 @@
 
 This extension provides the following features:
 
+### Type Inference
+
 * Provides precise return types for `config()` and `model()` functions.
 * Provides precise return types for `service()` and `single_service()` functions.
+
+### Rules
+
 * Checks if the string argument passed to `config()` or `model()` function is a valid class string extending `CodeIgniter\Config\BaseConfig` or `CodeIgniter\Model`, respectively. This can be turned off by setting `codeigniter.checkArgumentTypeOfFactories: false` in your `phpstan.neon`.
 * Checks if the string argument passed to `service()` or `single_service()` function is a valid service name. This can be turned off by setting `codeigniter.checkArgumentTypeOfServices: false` in your `phpstan.neon`.
 * Disallows instantiating cache handlers using `new` and suggests to use the `CacheFactory` class instead.