Add a filter to the events page on flutter.dev to show all events including past ones

[abdallahshaban557]

Describe the problem

On fluter.dev/events, we currently remove events that have already passed. We need to add a filter to show even previous events.

Expected fix

A new filter is available to show all past events or perhaps events from a specific time period.

On which browser(s) did you experience this issue?

No response

Additional context

No response

I would like to fix this problem.

• I will try and fix this problem on docs.flutter.dev.