docs: improve comments a bit

Author: kenjis

user_guide_src/source/models/model/001.php

@@ -1,15 +1,15 @@
 <?php
 
-// Create a new class manually
+// Create a new class manually.
 $userModel = new \App\Models\UserModel();
 
-// Create a new class with the model function
+// Create a new class with the model() function.
 $userModel = model('App\Models\UserModel', false);
 
-// Create a shared instance of the model
+// Create a shared instance of the model.
 $userModel = model('App\Models\UserModel');
 
-// Create shared instance with a supplied database connection
+// Create shared instance with a supplied database connection.
 // When no namespace is given, it will search through all namespaces
 // the system knows about and attempts to locate the UserModel class.
 $db        = db_connect('custom');