Add data.table.notebook.examples extension command

[RandomFractals]

package and ship this data table renderer extension with built-in Examples to let devs check out different notebook types with this extension without the need to download sample data files or notebook examples.

See GeoDataViewer map gallery for UI setup: https://github.com/RandomFractals/geo-data-viewer/releases/tag/v1.1.1

config: https://github.com/RandomFractals/geo-data-viewer/blob/master/src/config.ts

and examples gallery hookup: https://github.com/RandomFractals/geo-data-viewer/blob/master/src/extension.ts#L135

[RandomFractals]

configured notebooks examples quick pick list:

[RandomFractals]

to use generic Observable JS Data Table viewer notebook from built-in notebook examples, you need to install Observable JS vscode extension, and make sure to run Preview for the loaded .ojs notebook file:

[RandomFractals]

see: https://github.com/RandomFractals/vscode-data-table#-examples