Minutes of the call on 2021-04-09 + no call next week

Hi all,

today's minutes are:

        https://w3c.github.io/rdf-star/Minutes/2021-04-09.html

Note that we decided to skip next week, as the chair sent regrets...

If you think something has not been accurately reported, feel free to 
submit a PR.

Thanks to Ora for scribing.