Documentation update

Hi Brajesh-

Thanks for the useful plugin. I was looking through the files to understand how the plugin works and along the way made some edits/additions to the notes. Feel free to use them if you wish. 

One question I couldn't work out is what this note means:

```
 * Please note, this plugin requires the jQuery cookie plugin, which comes bundled with the bp-default theme and many BuddyPress themes.
 * If your theme does not include it, please copy it from bp-default/_inc/global.js and paste in your js file
```

I'm not sure what someone would copy out of the global.js file to enable the jQuery cookie plugin. It didn't look like the typical cookie plugin code had been copied into the file, and it doesn't look like it's being enqueued, but it works. :)

Thanks again,

-David