pas2jsdemoextension VS Code extension.

This package is a small adaptation of the VS Code extensions Hello World sample.

To install it in VS Code:

compile the program. You can do so in VS Code: just run the Build command.
run the package: This will start a second VS Code instance with the package installed.
To package it, you need to have vsce installed, so first it must be installed:
```
npm install -g vsce
```
Once installed, packaging can be done on the command-line run
```
vsce package
```

This will create a pas2jsdemoextension-0.0.1.vsix file which can be distributed and installed in VS Code.