Create /events tab

[shushugah]

Techworkerscoalition.org/events exists now with #360

What further improvements can be made?

• Make it easier to distinguish who/where an event it, perhaps with label tags
• add filtered events in different sub-pages, e.g https://techworkerscoalition.org/nyc/ could link to NYC and or Global events
• Improve image CSS formatting of events for both desktop and mobile
• Include TWC Community Guidelines/CoC under each event?