Update "Community" page w/ Summit 2020 info

[vannicer]

Actual Behaviour
https://www.hotosm.org/community/ needs updated links, info and picture from summit2020.hotosm.org

Expected Behaviour
Should have 2019 group picture, 2020 info from page and link to above.

[dakotabenjamin]

@vannicer what should we do with this now with the postponement?

[vannicer]

Can we A- Change to 2019 picture just for general purposes and then B for the text we can have: "Due to current uncertainties the HOT Summit is looking for new dates and venues for 2020. Keep an eye on HOT social media and Newsletters for the latest. You can view talks and information from previous HOT Summits here.