Docs: Clarify DestinationRule spec.trafficPolicy.connectionPool.tcp.maxConnections

**Bug description**

The documentation for the DestinationRule field `spec.trafficPolicy.connectionPool.tcp.maxConnections` states the following:

> Maximum number of HTTP1 /TCP connections to a destination host. Default 2^32-1.

This is misleading for two reasons:

1. It seems to imply that HTTP/2 connections are not subject to this limit, which per [Envoy's docs](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/circuit_breaker.proto#config-cluster-v3-circuitbreakers-thresholds) doesn't seem to be the case
2. This is much more of a nitpick, but per [Envoy's docs](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/upstream/circuit_breaking#arch-overview-circuit-break-cluster-maximum-connections) it's technically possible to surpass this limit, so it may be worth adding a caveat about that.

**Affected product area (please put an X in all that apply)**

[ ] Configuration Infrastructure
[X] Docs
[ ] Installation
[ ] Networking
[ ] Performance and Scalability
[ ] Policies and Telemetry
[ ] Security
[ ] Test and Release
[ ] User Experience