Support hiding interactions

[dbp]

Especially with the increasingly good support for VSCode, where sometimes the interactions isn't the primary mechanism of interaction, it would be nice if the interactions panel could be hidden.

[jpolitz]

This has been added (on horizon/in extension) via a template/hash parameter hideInteractions.

In the extension, this option is set by default.

Because it doesn't make much sense in CPO to run a program without using interactions, clicking Run shows the interactions.

I haven't added a "View" menu option or shortcut to do this when the page is open, just the initial config.

See 3f446ca