Mark old Live chart as legacy

[wgalanciak]

We need to add note to the old Live chart readme that is is no longer supported. We already have similar one for HQ chart readme.

[wgalanciak]

We can confirm that the readme file in the dev branch contains the new section at the beginning:
https://github.com/CodeTogether-Inc/CodeTogether-Deployment/tree/dev/charts/live

@waldekCT, I am moving this one forward.