docs: add section for "spark optimize"

Author: kenjis

user_guide_src/source/changelogs/v4.5.0.rst

@@ -25,6 +25,7 @@ Commands
 ========
 
 - Added ``spark optimize`` command to optimize configuration for production environment.
+  See :ref:`spark_optimize` for the details.
 - Added ``spark make:test`` command to generate a skeleton test file. See
   :ref:`cli-generators-make-test` for the details.
 - Added ``spark config:check`` command to check Config values. See

user_guide_src/source/installation/deployment.rst

@@ -15,6 +15,19 @@ things you can do to make your application run more efficiently.
 
 This section describes the optimization features that CodeIgniter provides.
 
+.. _spark_optimize:
+
+spark optimize
+==============
+
+.. versionadded:: 4.5.0
+
+The ``spark optimize`` command performs the following optimizations:
+
+- `Removing Dev Packages`_
+- Enabling `Config Caching`_
+- Enabling `FileLocator Caching`_
+
 Composer Optimization
 =====================