Update the open positions section

[aloisdg]

Hello,

Right now the "Open Positions" section is static. It would be nice if it was updated automatically each week.

The goal of this issue is to find a way to automate this. It could be with an Azure function, a GitHub Action or else. New jobs should be get from our WTTJ's page or from our welcomekit (more information on the kit).

Have fun :)

Issue talked with @aumeunier