Added Parser

- can parse a basic token list to an AST

Compiler/Lexer/TokenType.cs

@@ -0,0 +1,19 @@
+namespace Compiler.Lexer
+{
+    public enum TokenType
+    {
+        OpenParenthesisToken,
+        CloseParenthesisToken,
+        IntToken,
+        OpenBraceToken,
+        CloseBraceToken,
+        ReturnToken,
+        SemicolonToken,
+        IdentifierToken,
+        IntegerLiteralToken,
+        
+        //special Token to represent invalid matches
+        InvalidToken
+        
+    }
+}