Add solutions for part 1

tools/builtInChips/Inc16.hdl

@@ -0,0 +1,18 @@
+// This file is part of www.nand2tetris.org
+// and the book "The Elements of Computing Systems"
+// by Nisan and Schocken, MIT Press.
+// File name: tools/builtIn/Inc16.hdl
+
+/**
+ * 16-bit incrementer.  out = in + 1 (16-bit addition).
+ * Overflow is neither detected nor handled.
+ */
+
+CHIP Inc16 {
+
+    IN  in[16];
+    OUT out[16];
+
+    BUILTIN Inc16;
+}
+