look at adding more clarity on how customer impact of demoting a release depends on installer method used

[AmberAlston]

Some confusion came up on this, and as part of summarizing the convo I created this community article - https://community.replicated.com/t/what-happens-downstream-when-i-demote-a-release-in-vendor-portal-removing-a-channel-release/1565

We mentioned demoting a release in a couple of places, https://docs.replicated.com/vendor/releases-about#demotion & https://docs.replicated.com/vendor/releases-about#demotion but it's not as clear as it could be if that removes it from the customer seeing it or not.

When we have time, it'd be nice to see if a bit of this article detail can be integrated into these docs without adding a ton of content

[AmberAlston]

Given this PR #3434 I consider this issue solved. thank you!