add comment in class "NoTerminalExpression/TerminalExpression" and upd README.rst

Behavioral/Interpreter/AndExp.php

@@ -2,6 +2,9 @@
 
 namespace DesignPatterns\Behavioral\Interpreter;
 
+/**
+ * This NoTerminalExpression
+ */
 class AndExp extends AbstractExp
 {
     public function __construct(private AbstractExp $first, private AbstractExp $second)

Behavioral/Interpreter/OrExp.php

@@ -2,6 +2,9 @@
 
 namespace DesignPatterns\Behavioral\Interpreter;
 
+/**
+ * This NoTerminalExpression
+ */
 class OrExp extends AbstractExp
 {
     public function __construct(private AbstractExp $first, private AbstractExp $second)

Behavioral/Interpreter/README.rst

@@ -4,7 +4,8 @@
 Purpose
 -------
 
-For a given language, it defines the representation of its grammar,
+For a given language, it defines the representation of its grammar as
+"No Terminal Expression" and "Terminal Expression",
 as well as an interpreter for the sentences of that language.
 
 Examples

Behavioral/Interpreter/VariableExp.php

@@ -2,6 +2,9 @@
 
 namespace DesignPatterns\Behavioral\Interpreter;
 
+/**
+ * This TerminalExpression
+ */
 class VariableExp extends AbstractExp
 {
     public function __construct(private string $name)