Fix: some sample codes

README.md

@@ -785,13 +785,13 @@ For example:
 
 ```js
 sourceFile = readlineSync.questionPath('Read from :', {
-  isFile: true,
-  exists: true
+  isFile: true
 });
 console.log('-- sourceFile: ' + sourceFile);
 
 saveDir = readlineSync.questionPath('Save to :', {
   isDirectory: true,
+  exists: null,
   create: true
 });
 console.log('-- saveDir: ' + saveDir);

package.json

@@ -1,6 +1,6 @@
 {
   "name": "readline-sync",
-  "version": "1.2.9",
+  "version": "1.2.10",
   "title": "readlineSync",
   "description": "Synchronous Readline for interactively running to have a conversation with the user via a console(TTY).",
   "keywords": [