[Documentation] Update GETTING_STARTED guide with missing examples of how to use Terra Draw with different mapping libraries

[JamesLMilner]

This ticket covers updating the GETTING_STARTED guide with code for the missing examples for OpenLayers, MapboxGL, MapLibreGL and also if you are up to it adding in the ArcGIS Maps SDK example too. The development folder has an example of how to create each of these so this will be a good point of reference on how to do this.

OpenLayers Coming soon - please see development folder for example for now.

MapboxGL JS Coming soon - please see development folder for example for now.

MapLibreGL JS Coming soon - please see development folder for example for now.