docs: adding expose depoyed chart hip

[mrlunchbox777]

Adding a HIP to expose the currently deployed chart at render time.

[mrlunchbox777]

@scottrigby @gjenkins8 here is the hip we talked about at contribfest

[danilo-patrucco]

+1

[mrlunchbox777]

Some notes that were brought up to improve the proposal were to:

1. Consider the various states that .Deployed chart could be in (failed/rollback/etc), what to collect/show (size/speed implications), and how to control/represent the various options
2. Add notes for the existing flux use case

[mrlunchbox777]

Some notes that were brought up to improve the proposal were to:

1. Consider the various states that .Deployed chart could be in (failed/rollback/etc), what to collect/show (size/speed implications), and how to control/represent the various options
2. Add notes for the existing flux use case

Here is an example of getting flux CRs to control if an upgrade job runs. It was part of this MR. It was used for a default name change on immutable resources by deleting them in a hook.