Added Parser

- can parse a basic token list to an AST

Compiler/Parser/Exceptions/UnexpectedTokenException.cs

@@ -0,0 +1,20 @@
+using System;
+using Compiler.Lexer;
+
+namespace Compiler.Parser.Exceptions
+{
+    public class UnexpectedTokenException : Exception
+    {
+        public TokenType expected { get; set; }
+        public TokenType got { get; set; }
+
+        public override string Message { get; }
+
+        public UnexpectedTokenException(TokenType expected, TokenType got)
+        {
+            this.expected = expected;
+            this.got = got;
+            this.Message = "Unexpected Token " + got + ". Expected: " + expected;
+        }
+    }
+}