adds more info for step 10, small README updates

Author: minaorangina

README.md

@@ -17,6 +17,8 @@ Make sure to checkout to the relevant branch before continuing.
 
 You will see code snippets throughout the walkthrough.  Try to resist the urge to copy and paste - you will learn **much** more if you get into the habit of typing things out.
 
+You might want to test out small bits of code and run them before adding it to your project.  For this, you can use [repl.it](https://repl.it/) if you like.
+
 
 Your mentor is there to help you.  Don't let them die of boredom - talk to them and ask questions!
 

step10.md

@@ -6,7 +6,7 @@ git merge step9
  ```
 ---
 
-There's a new file in the public folder, `script.js`.  Don't worry about what all the code means, just know that it's responsible for sending a request to `GET` old blogposts and display them on the page underneath "Recent Posts".  
+There's a new file in the public folder, `script.js`.  Don't worry about what all the code means, just know that it's responsible for sending a request to `GET` old blog posts and display them on the page underneath "Recent Posts".  
 
 You probably want to handle the request from that `script.js` file in your server code...
 
@@ -15,6 +15,24 @@ You probably want to handle the request from that `script.js` file in your serve
 
 At the moment, your blog posts are reaching the server, but aren't being saved anywhere.  They just disappear into a cloud of bits and bytes.  We need to find a way to save them so that you can retrieve them later.
 
+You'll note that in the `lib` folder there's a new file called `posts.json`.  
+
+JSON is a type of file for structuring data in a readable way.  They're also a really popular format for sending data across the web.
+
+JSON is a string representation of a Javascript object.  JSON objects convert really easily to Javascript objects, and vice versa, with `JSON.parse()` and `JSON.stringify()`.  
+
+(If you're not sure about Javascript objects, have a chat with your mentor and your team.)
+
+You'll see there's already one blog post sitting in `posts.json`.  The format is:
+```js
+{
+    [timestamp]: [blog post message]
+}
+```
+We've used a timestamp as the key so that the blog posts are listed in chronological order.  Also, it's a record of when the blog post was created.  
+
+To add your own blog posts to `posts.json`, you will need to read the file from the hard drive, add to it, then write it back.  
+
 You'll remember that `fs.readFile()` is the method responsible for reading files from your hard drive.  Well, `fs.writeFile()` is a method that allows you to write data into a file.
 
 ```js
@@ -24,27 +42,31 @@ fs.writeFile('path/to/file', yourData, (error) {
 });
 ```
 
-You'll note that in the `lib` folder there's a new file called `posts.json`.  
-
-JSON is a type of file for structuring data in a readable way.  JSON objects convert really easily to Javascript objects, and vice versa, with `JSON.parse()` and `JSON.stringify()`.  
-
-(If you're not sure about Javascript objects, have a chat with your mentor and your team.)
 
 **Modify your server code to:**
-1. **Save your blogpost data into `posts.json`**
-2. **Handle the `script.js` request**
+1. **Save your blog post data into `posts.json`**
+2. **Handle the `script.js` request coming into the server**
 3. **Retrieve all your posts and send them back to `script.js`**
 
+
+* You'll want to make sure your blog posts are also added with a timestamp.  You can get the current unix timestamp using `Date.now()`.
+
+* `fs.writeFile()` automatically overwrites the whole file.  Chances are you don't want to lose all your old blog posts, so think about how you can use both `fs.readFile()` and `fs.writeFile()` to prevent overwriting.
+
+* The code in `script.js` is expecting to receive a JSON object.  Remember your http headers!
+---
+
 If all goes well, you should have a fully functional CMS!
 
 
 🎉CONGRATULATIONS!!🎉
 ===
 
----
+
 Want more?  Then head over to...  
 
 ## [**Stretch goals >>> **](stretch.md)
 ---
 ## Keywords
 * [JSON](http://www.w3schools.com/js/js_json.asp)
+* [timestamp](http://www.w3schools.com/jsref/jsref_now.asp)

stretch.md

@@ -13,11 +13,11 @@ It would be a great idea to create a new branch on Git for yourself, so you can
 ### More modularisation!
 Currently, `handler.js` is a combination of decisions and actions.  The decisions are the  the if-else branches that look at the request url, and the actions are the bits inside the curly brackets.
 
-You could split out the decision part to its own file, `routes.js`.  Then the actual actions (so, the functions you call) would remain in `handler.js`.  `routes.js` 
+You could split out the decision part to its own file, `routes.js`.  Then the actual actions (so, the functions you call) would remain in `handler.js`.  `routes.js`
 
 
 ### Use a database
-Instead of writing to a file on your hard drive, you could save your blogposts in a database, which would be much quicker in terms of performance if there was a lot of data.
+Instead of writing to a file on your hard drive, you could save your blog posts in a database, which would be much quicker in terms of performance if there was a lot of data.
 
 * [MongoDB](https://docs.mongodb.org/getting-started/node/)
 [Redis]