D45 patch what you can do (tableau#161)

* Update readme.md (tableau#152)

Fixed typo of the word 'extension' in third sentence.

* Update trex_configure.md (tableau#156)

Fixed JavaScript typo found by @jakkyn

* Update trex_getstarted.md (tableau#157)

Fixed error found by @jakkyn - In the Choose dialog box, the Choose button is now My Extensions.

* Update trex_overview.md

Add a what you can do list

Tutorial/readme.md

@@ -2,7 +2,7 @@
 
 This project contains a tutorial designed to explain the various components of authoring and using a Dashboard Extension in Tableau.
 
-This tutorial demonstrates a number of different aspects of the Dashboard Extensions API. The goal of this extenison is to display a data table summarizing the selected marks on a particular worksheet on a dashboard (similar to clicking view data on a tooltip). When the selected marks change, we want to update the data table with the newly selected marks. Then we will add functionality which allows the user to click on any column of data in the selected marks and filter the viz down to the domain of that column.
+This tutorial demonstrates a number of different aspects of the Dashboard Extensions API. The goal of this extension is to display a data table summarizing the selected marks on a particular worksheet on a dashboard (similar to clicking view data on a tooltip). When the selected marks change, we want to update the data table with the newly selected marks. Then we will add functionality which allows the user to click on any column of data in the selected marks and filter the viz down to the domain of that column.
 
 ### Prerequisites
 

docs/trex_configure.md

@@ -84,7 +84,7 @@ $(document).ready(function () {
 })();  
 
 ```
-In the JavScript code for the popup dialog window, you would add your code for initializing the dialog and for setting and saving the configuration settings.
+In the JavaScript code for the popup dialog window, you would add your code for initializing the dialog and for setting and saving the configuration settings.
 
 ```javascript
 

docs/trex_getstarted.md

@@ -92,7 +92,7 @@ To use the dashboard extension samples, you need to start up a web server on you
 2. In the dashboard, under **Objects**, select **Extension** and drag it on to the dashboard.  
    ![]({{site.baseurl}}/assets/frelard_objects_extension.png){:height="25%" width="25%"}
 
-3. In the **Choose an Extension** dialog box, click **Choose**. 
+3. In the **Choose an Extension** dialog box, click **My Extensions**. 
  Every Tableau extension has a manifest file (`.trex`) that describes the extension and identifies the location of the web application. 
 4. Browse to the directory where the samples are located. For example, if you downloaded or cloned the GitHub repository, go to `\extensions-api\Samples`. 
 5. Open the `DataSources.trex` file.     

docs/trex_overview.md

@@ -12,10 +12,18 @@ layout: docs
 {:toc}
 
 ## Components of a Tableau dashboard extension 
-A Tableau extension consists of a manifest file (`.trex`), a web page that uses a Tableau-provided JavaScript library, and the JavaScript file (or files) that contain your extension logic. The Tableau extensions are supported on Tableau Desktop.
+A Tableau extension consists of a manifest file (`.trex`), a web page that uses a Tableau-provided JavaScript library, and the JavaScript file (or files) that contain your extension logic. The Tableau extensions are supported on Tableau Desktop, Tableau Server, and Tableau Online.
 
 ![]({{site.baseurl}}/assets/extensions_dashboard_diagram.png) 
 
+## What can you do with a dashboard extension? 
+
+Plenty! Using the Extensions API, you can create dashboard extensions that enable customers to integrate and interact with data from other applications directly in Tableau.
+
+* Integrate with third-party APIs inside the dashboard.
+* Use third-party charting libraries like `d3.js` to add custom visualizations.
+* Create an extension that has write-back functionality, so users can modify data in a viz and have that change automatically update the source data in the database or web application.
+* Build custom viz and interactivity types, such as a filter replacement with a custom interface and network diagram.
 
 ## Extensions API library
 
@@ -29,4 +37,4 @@ The Extensions API and the Embedded API (also known as the [JavaScript API](http
 * You can use the Embedded API for embedding Tableau dashboards in web pages (for example, blog posts), or in line of business applications.
 * You can use the Extensions API for integrating web applications into zones in Tableau dashboards. 
 
-The Extensions API and Embedded API share a similar programming model, but there are differences. The two APIs are not designed to be used together. In the Embedded API, the `Viz` or `VizManager` is the highest-level object. However, in the Extensions API there is no object model or concept for a `Viz` or `VizManager`. For the Extensions API, the workbook is the highest-level object a developer interacts with.
+The Extensions API and Embedded API share a similar programming model, but there are differences. The two APIs are not designed to be used together. In the Embedded API, the `Viz` or `VizManager` is the highest-level object. However, in the Extensions API there is no object model or concept for a `Viz` or `VizManager`. For the Extensions API, the workbook is the highest-level object a developer interacts with.