Add banner to landing website for important updates and warnings

[incertum]

I find banners on top of websites extremely helpful to communicate important updates. For example, it is a common practice to communicate planned outages or production freezes. That way we may increase our chances of setting expectations and avoid frustrations when upgrading Falco.

For the Falco 0.37.0 release it could highlight the following:

• Falco rules now follow semantic versioning and the most recent Falco rules release requires Falco >= 0.37.0
• Falco will deprecate the following configs xyz in Falco 0.38, start using the new config options today (most notably the new engine config)
• The -k flag no longer exists. Instead, we've introduced a new opt-in k8smeta plugin, although it isn't necessary for most Falco use cases. This is because the familiar k8s fields are extracted from the container runtime socket concurrently while looking up container images.
• Check out the new Supported Fields
• ...

or similar ...

[LucaGuerra]

Hey Melissa, this is now already in the website! We have used this to display a graduation banner for a month. We can use that banner to display any information we please.

[incertum]

Saw this, amazing! Thanks!