+some refinements to the readme

## Installing the plug-ins

The TDL tools are available as a set of Eclipse plug-ins. You need to first be able to run Eclipse. The [Eclipse Neon Modeling Tools](http://www.eclipse.org/downloads/packages/eclipse-modeling-tools/neon3) distribution contains most of the necessary prerequisites for the TDL tools.

The TDL tools are available as a set of Eclipse plug-ins. You need to first be able to run Eclipse. The [Eclipse Neon Modeling Tools](http://www.eclipse.org/downloads/packages/eclipse-modeling-tools/neon3) distribution contains most of the necessary prerequisites for the TDL tools. You will also need to install [Sirius(https://www.eclipse.org/sirius/)] and [Xtext(http://www.eclipse.org/Xtext)] from the Eclipse Marketplace as the TDL tools depend on them.

Once Eclipse is up and running, you need to add the [update site](http://build.tdl.etsi.org) for the TDL tools: (http://build.tdl.etsi.org)

After the update site is added, the list of plug-ins and features shall be shown in the installation dialog. Select the desired features and proceed with the installation, which will require Eclipse to be restarted once the installation is finished. 

After the update site is added, the list of plug-ins and features shall be shown in the installation dialog (menu item Install New Software..). Select the desired features and proceed with the installation, which will require Eclipse to be restarted once the installation is finished. 

## Using the plug-ins

 * To create a new TDL model by means of the TDLan2 textual representation, right click on a project or a folder in the package explorer and select New -> File, type the filename ending with `.tdlan2` and the corresponding editor shall be automatically opened.

 * To create a new TDL model by means of the TDPan2 textual representation for structured test objectives, right click on a project or a folder in the package explorer and select New -> File, type the filename ending with `.tplan2` and the corresponding editor shall be automatically opened.

 * To translate a TDL model from the TDLan2 textual representation to the XF format (or the other way around), open the source model and press the "T" icon on the toolbar. The resulting model shall be stored in the same folder as the source model with the type of the model (`.tdlan2` or `.tdl`) appended to the name of the source model.

## Setting up a local environment for development and testing

 * Check out the repository

 * Import the plug-ins in the workspace

 * Import the plug-ins in the Eclipse workspace

 * Generate the meta-model code

  * Open the `tdl.genmodel` 

  * Right click on the top-node and generate model code 

  * Right click and select Run As -> MWE2 Workflow

  * Optionally (or alternatively) repeat the same steps for the `GenerateTPLan2.mwe` (for editing structured test objectives)

  * Optionally (or alternatively) repeat the same steps for the `GenerateData.mwe` (for the graphical viewer)