Default chart configuration to target more scalable needs (non-hobbyist)

[tiina303]

Is your feature request related to a problem?

We don't really have good guides around how to get to a more scalable PostHog install and some stuff is hard to change later. Current docs only address values file changes: https://posthog.com/docs/self-host/deploy/configuration#scaling-up

Describe the solution you'd like

We'll have clear guides for these 3 use cases:

1. 10$ / 20$ hobby version one can use for up to ? events and it's a bit slow to load potentially?
2. Potentially: 60$ small setup (on DigitalOcean only as GCP/AWS it's already more expensive, so why not go the scalable route?) scales up to ? events
3. (>100$) auto-scalable setup for any platform with guidance on cluster & node sizing. This is what the chart default values will target.

We'll need:

1. Resource limits https://github.com/PostHog/charts-clickhouse/pull/159
2. Stateful services default sizes to upsize
3. Doc to include cluster and node size recommendation (for auto-scalable and small setup)
4. Doc for how to get minimal / cheaper setup
5. stateless services autoscaling (hpa)
6. Doc for scaling up (links to migration guide)

Describe alternatives you've considered

Keep the minimal chart as the default.

Additional notes

If the auto-scalable default version close to the minimal price we can get then we just have two: hobbyist + scalable. If it is significantly more than we'll want to keep the DO 60$ option. If significantly more than 100$ we might want keep info for aws/gcp/azure for minimal setups too which are about 100$ iirc)

Related https://github.com/PostHog/vpc/issues/149