Communication tools of the group

[xfq]

https://w3c.github.io/miniapp/charters/wg-2020.html#communication

This group primarily conducts its technical work on the public-miniapps-wg@w3.org and on GitHub issues. Other communication tools are allowed if considerable number of the group participants decide to embrace them.

We ought to quantify "considerable number", such as "80% of the participants" and also add "Any decision to use other communication tools must be reevaluated if further W3C Members join the Working Group".

(This comment comes from the W3C Management review of this charter.)