Review definitons of types of groups (both technical and non-technical)

[AevaOnline]

The OpenSSF Charter relies on the following Terms:

• Governing Board
• Committees (subordinate to the Governing Board, not technical)
• Technical Advisory Council
• Working Groups
• Projects
• Technical Initiatives (superset of both Working Groups and Projects, must be Chartered, subordinate to the Technical Advisory Council)

It would be good to document exactly what we mean by these Terms, as well as any colloquial terms, within this repo, and in a way that is compatible with the Charter, and to clarify the differences (e.g., between Projects and Working groups).

If other repos in the OSSF org use definitions that don't align to the Charter, those should be updated, as changes to the Charter require a 2/3rds majority vote in the GB.