charter: Make per-project TDCs explicit

[wking]

If the set of spec maintainers and the set of runC maintainers is
identical, spec maintainers who are also runC developers might be tempted
to skew the spec towards already-implemented-in-runC semantics, despite the
existence of potentially cleaner models in other implementations. To avoid
bias in the spec, it makes sense to explicitly declare per-project TDCs.
That allows developers associated with any implemention (whether or not
that implementation is an OCI Project) to be on the spec TDC without
requiring them to also assume responsibility for runC itself.

For background discussion, see this thread.

With per-project institutions, it makes sense for the OCI to have a
mechanism for adding/removing projects, and the TOB seems like the
obvious choice to do that (the LF board probably doesn't care about
this level of granularity, the other TDCs are focused on other
projects, and OCI Members probably shouldn't be able to launch OCI
Projects independently).

This builds on #3, and but I'm happy to rebase it if #3 turns out to
be controversial.

[wking]

If the per-project-TDC approach sounds reasonable, we should probably override the current:

 … the project’s day-to-day technical governance in a [Maintainer’s Guide](https://github.com/opencontainers/runc/blob/master/MAINTAINERS_GUIDE.md). 

In content/pressrelease-july-2015.md with a mutable table of projects and links to each project's docs and current TDC members (since there will no longer be a single TDC to link to). I'm not sure what the policy is on updating blog-ish posts like that press release. Do we leave them as published, or do we update them to reflect the current reality as it diverges from the post-time reality?

I'd suggest either listing projects under about.md, listing them in a new page with it's own navbar link, or just pointing folks at the GitHub organization. We already have:

… Projects associated to the Open Container Initiative can be found at [https://github.com/opencontainers](https://github.com/opencontainers)…

In about.md, and that may be sufficient.

It would be nice to list TDC memebers and governance rules consistently for each project (if we go with per-project TDCs). The runC repository lists the rules in MAINTAINERS_GUIDE.md and lists maintainers in MAINTAINERS, but the “Maintainers” label is only suggested in the currently-live charter (§4.b):

viii. Creating, maintaining and following governance guidelines for the TDC, including:
  1. the establishment of roles (e.g. Maintainer, Contributor) and each role’s responsibilities,

Maybe we should use a generic GOVERNANCE.md as a standard bridge between the OCI charter and whatever local structure the TDC has chosen. That would make it easy for the runC TDC (for example), to clarify that the TDC was composed entirely of the Maintainer group, and to reference the list and maintainer guide for more information on that group.

[wking]

OCI members can figure this out amongst themselves, and don't have a channel for input from external parties like me.

[wking]

The adopted charter allows the TOB to establish additional TDCs per OCI Project if it wants to (§6.d).