Conference: Call for abstracts and intoduction text

[rantahar]

• Also moved social session to day 1, so that people don't leave during it...

Todo:

• Create the call on Indigo and update with link

Review:

• I'm trying to be as inclusive as possible, does that come across?
• Does this reflect our discussions about topics and contribution types?

[samumantha]

@nordic-rse/nordic-rse-team : Could we also have a session/invite talks on research support/mentoring/training? :)

[rantahar]

Thanks @samumantha. @mtomasini, I think we should merge and maybe improve in a new PR?