Allow temporarily disabling use of certain features. Useful for large site operators to push people to newer APIs while still keeping the breakage short and contained. This should be an array, where a key is a feature name and the value is an array of shutdown arrays, each containing the following keys:

• 'start' - Shutdown start, parsed with strtotime(). (required)
• 'end' - Shutdown end, parsed with strtotime(). (required)
• 'percentage' - Number between 0 and 100. If set, only a certain percentage of requests will be blocked.

For example:

$wgFeatureShutdown = [
	'pre-1.24-tokens' => [
		[
			'start' => '2021-07-01T00:00 +00:00',
			'end' => '2021-08-01T00:00 +00:00',
			'percentage' => 50,
		],
	],
];