moved lexer functions to Lexer.c and included Lexer.c

Exercise 2/C/Lexer.c

@@ -0,0 +1,31 @@
+#include "Lexer.h"
+
+int start(char* src) {
+    // if (src != NULL) {
+    //     return _GET_NEXT_CHARACTER_;
+    // } else {
+    //     return _STOP_;
+    // }
+
+    return _STOP_; // placeholder
+}
+
+int getNextCharacter() {
+    return _STOP_; // placeholder
+}
+
+int readIdentifier() {
+    return _STOP_; // placeholder
+}
+
+int readNumLit() {
+    return _STOP_; // placeholder
+}
+
+int readOperator() {
+    return _STOP_; // placeholder
+}
+
+int readPunctuation() {
+    return _STOP_; // placeholder
+}