[Tc] A draft community governance

Hi all, I found some SIGs are adding committers recently. And some new SIGs with new projects(repos) are being created. Even it is in very early stage of the community, I think we'd better to have a governance to make such changes serious. If you have comments, please leave it at[1]. Your opinion matters. [1] https://gitee.com/open_euler/dashboard/issues?id=I1838P Fred 李永乐