Remove outdated helm install information around accessing ecosystem services

[eamansour]

Some parts of the ecosystem helm installation process are outdated and is confusing to users. These include:

• Mentioning that users can provide an IP address for the externalHostname value - This is no longer true since Ingress doesn't allow IP addresses, which would cause users to encounter errors
• Mentioning that Ingress is "enabled by default", implying that it could be disabled - This is no longer the case since access to services via NodePorts has been completely replaced with Ingress, so the services can only be accessed via Ingress now
• Mentioning that the ecosystem's use of Dex is still under development - This has been stable for several releases now, so that line can be removed
• Mentioning that the bootstrap needs to be "reconfigured" - This isn't true since we already mention the bootstrap how the bootstrap can be accessed in the previous section

The changes in this PR resolve the above issues.

[eamansour]

Closed in favour of #837