Stabilize terminal access APIs

[Tyriar]

These ones seem like no brainers:

export namespace window {
	/**
	 * The currently opened terminals or an empty array.
	 */
	export const terminals: ReadonlyArray<Terminal>;

	/**
	 * An [event](#Event) which fires when a terminal has been created, either through the
	 * [createTerminal](#window.createTerminal) API or commands.
	 */
	export const onDidOpenTerminal: Event<Terminal>;
}

Both live share and python are using/want to use these.

[Maples7]

Great feature!

And wouldn't it be better to cd to the directory of the open focus file after the terminal is launched? I am trying to write an extension to achieve this feature but do not find the activation event while a terminal is launched. So good to know this is planned.

[Tyriar]

FYI @jrieken

[Maples7]

I've published an extension to achieve the function I mentioned above.

Terminal In Place

[Tyriar]

Verifier please make sure the APIs exist and are functional

[dziarkoaka1001]

Dzialaja należycie :)