Added an interactive shell, well the start of one.

lox.c

@@ -49,5 +49,14 @@ char* GetFileContents(const char* path) {
 }
 
 void RunPrompt(void) {
-    printf("> \n");
+    printf("> ");
+    char input[256];
+
+    while(fgets(input, sizeof input, stdin) != NULL) {
+        if (strcmp(input, "q\n") == 0) break;
+        
+        printf("E_NOT_IMPLEMENTED\n");
+
+        printf("> ");
+    }
 }