Look into using webhooks for listening to new deployments

[half0wl]

Context:

railway-chord/src/main.ts

Lines 50 to 73 in 535e6fa

	/**
	* This is the main event loop that refreshes a project's deployments and
	* plugins every n seconds (where n=`REFRESH_INTERVAL_SECONDS`) and pushes
	* the logs of each deployment/plugin into Vector.
	*
	* The major limitation of this approach is Railway's rate limit - each
	* account is limited to 1k requests per day [0]. At the current default
	* refresh interval of 15 mins, that works out to 96 requests every 24
	* hours for project data per-project. I'm not sure if the WS subscriptions
	* are subject to this rate limit. In theory, rate limits should apply
	* per-request instead of per-WS message, which implies each WS connection
	* counts toward the rate limit. This effectively means that we're making
	* `(1 + (services+plugins)) * (86400 / REFRESH_INTERVAL_SECONDS)` requests
	* every 24hours for each project.
	*
	* An alternative/better way of doing this is through Railway's webhooks.
	* We can subscribe to new deployments. However, this approach misses out
	* on plugin creation/deletion: when a plugin is created, logs will only
	* get pushed after restarting this service. Conversely, when a plugin is
	* deleted, we'll have no way of knowing (would subscribing to logs of a
	* deleted plugin error out?).
	*
	* [0] https://docs.railway.app/reference/public-api#rate-limits
	*/