Add 'trainings' contact details

[ehuelsmann]

There used to be scheduled trainings listed. There aren't any at this time, however, training contact details for those who want to receive trainings are to be added to the site.

[ehuelsmann]

@ferki assuming you'll be the trainer, could you please add the details you want for this issue? Thanks in advance!

[ferki]

I'll find out the status of the previous training offerings, but I believe they are not available today.

And we can either add a generic contact for training queries and/or show open events in the sidebar.

I consider this issue a relatively low priority, as the website is usable without it, and I believe there's no pressure to actively advertise training offerings as of this moment. Still, it would be a nice addition both to the portfolio and as a website feature.