Reintroduce old Docsy-overrides where needed/wanted

[nate-double-u]

Follow up to #803, it looks like we've lost the old version warning banner. Do we still want/need it? if so, we should reintroduce it.

There are several overrides that got dropped and could be reintroduced. The majority of them can be found in PR https://github.com/cncf/docsy/pull/2

[nate-double-u]

The banner code can be found here: https://github.com/cncf/docsy/blob/etcd.io/layouts/partials/version-banner.html

[Sadamingh]

Hi @nate-double-u, if the banner is needed, I can start to work on these. Need information on which versions I have to add those banners. Also, enabling the banners will possibly remove these issues like https://github.com/etcd-io/website/issues/837.

/cc @jmhbnz

[moficodes]

/assign

[jberkus]

Yes, we still want the warning banners.

[nate-double-u]

Need information on which versions I have to add those banners

I think the banners would be needed for all the versions except current. All the previous versions would say something like 'archived,' while the next version would say something like 'proposed.' (I can't remember exactly the specific wording, but that's it in a nutshell)

[jmhbnz]

The partial for version banner has now been reintroduced, thanks @moficodes!

Are there any other overrides we want to reintroduce or should we close this now?