Add an example of a 'Button Plugin' on the main window (3D Viewer)

[NicolasRichel]

Add a section or a paragraph to show how to add a "Button Plugin" on the 3D Viewer window by mean of the addToWindows option.

Example:

const viewer = makeBIMDataViewer({ /* viewer config */ });

viewer.registerPlugin({
  name: 'buttonPlugin',
  component: {
    name: 'ButtonPluginComponent',
    template: '<div>Hello World !</div>'
  },
  button: {
    position: 'right',
    content: 'simple',
  },
  addToWindows: [ '3d' ] // <-- Here is the trick :)
});

viewer.mount('#viewerId', '3d');

[NicolasRichel]

Je verrais bien ça dans la section Add plugins on windows du step by step tutorial.