Add links to Mods Developer Hub

[hski-github]

If you browse the API documentation and getting started, there are quite a couple of things not explained here like how to work with marking, tool tip and color axis, but there are examples in the developer hub.

Please add a link to the Mods developer hub https://community.spotfire.com/articles/spotfire/spotfire-mods-developers-hub-welcome/ in general to the top right and ideally also elsewhere like in the Getting started section and at other places, so that people know, there is additional information in the Mod Developer Hub.

[mrylande]

Hi Holger! Your feedback is very helpful in our efforts to provide the best possible developer experience when working with the Spotfire APIs and SDKs.

Regards,
Magnus