Created Solid World and Newsletter Teams

[jaxoncreed]

This PR proposes the Solid World and Solid Newsletter teams along with some of their responsibilities.

[jeff-zucker]

Question - would all members of these teams also be voting members of the Solid Team itself?

[jeff-zucker]

Possible addition to responsibilities of each team :

The team should make an effort to ensure that socially beneficial organizations and underrepresented voices are part of the target audience and highlighted in the content.

[jaxoncreed]

Good points, @jeff-zucker . I've updated the copy.