Update the website

[geohacker]

• Update the website
  • Add notice about postponement to 2021
  • Add information about planned online conference
• Update the OSM Wiki page

[iyan31]

We need to update the Wiki too, should that be part of this issue or separate ones?

[seav]

It can be part of this issue if we create checkbox lists on the original ticket. Or it can also be a separate issue if we want to assign different people.

[iyan31]

let's put that here, for now, I volunteer myself to update the wiki