Formalize process to add new Django Commons administrators

[tim-schilling]

From a technical perspective, having some familiarity with Python packaging is beneficial. Being able to work with GitHub organizations, repos, and actions is also helpful. However, the major requirement for admins is that they are trusted by the community. Admins will have keys to several packages that will be in use of thousands of applications.

Perhaps we could do a signature approach of getting 10 other DSF individual members to vouch for you?