META: Improve genesis override documentation in the CLI help page

[Olshansk]

Context:

Our team spend a bit of time trying to figure out how to update chain_id before we found this link: https://docs.ignite.com/v0.25/kb/genesis

Here is context:

Acceptance Criteria:

There's an opportunity to update the ignite --help manual pages to avoid future developers spending time here too.

A concrete suggestion would be to link https://docs.ignite.com/v0.25/kb/genesis under ignite init --help for delays on genesis overrides.