[Meta] Developer Url & linking documentation & guidelines

[stacey-gammon]

We need to clarify:

• core.navigateToApp vs url generators
• Document guidance around when to use url generators, and when to use core.navigateToApp('settings', {..}) vs settings.navigateTo({..}).
• How to handle migrations and what state is part of a public API.
• How to avoid a full page refresh when building hrefs to other parts of Kibana (like in Markdown)

etc, etc. Opening this as a meta issue to track these things. TODO: link out to relevant issues.

[elasticmachine]

Pinging @elastic/kibana-platform (Team:Platform)

[elasticmachine]

Pinging @elastic/kibana-app-arch (Team:AppArch)

[pgayvallet]

when to use core.navigateToApp('settings', {..}) vs settings.navigateTo({..}).

Directly related: #66682

[Dosant]

This pr documents most of bullet points from the issue description: #76888
Not sure if this issue can be closed or if we are good with existing guide for now.
In case something else needs to be documented on this topic, the navigation.ascii page is a good place to added it to

[stacey-gammon]

👍 closed by #76888